On the morning of her first day as a surgical intern at Seattle Grace Hospital, Meredith Grey is running late as she recovers from a one-night stand and prepares for her first day. Meredith quickly befriends George O'Malley, who's quirky, yet lovable, Cristina Yang, a highly competitive woman, and Izzie Stevens, a model turned surgical intern. Each of the new interns get assigned to Dr. Miranda Bailey, who past interns have dubbed "the Nazi".

Meredith's first patient, a young beauty pageant contestant, recently began having severe, life-threatening seizures and Meredith uncovers that she'll need brain surgery to save her life. However, things take a turn when the neurosurgeon, Dr. Derek Shepard, happens to be Meredith's one-night stand. He wants their brief relationship to progress into something more, but Meredith is firm on her stance - their relationship should remain strictly professional.

The surgical staff tries to stay positive when a young woman, despite brain surgery, is clinging to life after a brutal attempted rape. Meanwhile, Meredith risks her spot in the intern program when she crosses the line in order to save a newborn suffering from a undiagnosed heart condition. The other interns learn that in order to be a good surgeon and doctor, much more than medial knowledge is needed.

On the day of a bike race, injured individuals flood into the hospital, including a pedestrian who is left brain dead. Seeing that he has no chance of ever waking up, Cristina and Izzie wish to use his organs for organ donation, but find that the process is an emotional one. George gets assigned to Mack, a good friend of Chief Webber, and constantly flirts with George. Meanwhile, Meredith continues to try to distance herself from Derek and is forced to deal with Alex's big ego, but through the day, Meredith begins to realize the key to winning the battle.

While George begins to feel that he's loosing his masculinity due to Izzie and Meredith treating him like a sister, Izzie's newest patient may lose his masculinity to prostate cancer. Cristina assigns herself to a sick woman, who she believes will need surgery, but ends up learning more from the woman then standing in on a surgery would ever give her. Meredith faces the reality of her mother's Alzheimer's when Derek treats a patient with nails in his brain. Meanwhile, Alex tapes up pictures of Izzie's racy spread all over the locker room.

Meredith realizes the responsibility of adulthood when her mother has to sign all of her assets over to her. Izzie decides to throw a party for her boyfriend, Hank, and the scale of the party, which Meredith is unaware of, increases throughout the day. After popping a glove during a heart surgery, Meredith fears that she damaged the patient's heart and has to face a meeting with the chief and lawyers who will determine her future as a doctor. Meanwhile, sparks start to fly between Cristina and Burke, and Meredith and Derek's relationship is exposed when Bailey catches them together at the party.

The interns are speechless when a woman comes in with a large, record-breaking tumor, but unfortunately for the woman, her outlook isn't good. Derek and Meredith's jobs are at risk now that Bailey knows about their relationship, and Dr. Bailey makes it clear that Derek better not give Meredith special treatment. Meanwhile, Izzie urges George to ask Meredith out, and Cristina and Burke's relationship continues to progress.

Derek and Meredith try to spend a night together at Meredith's, but their appearance the next morning does more harm than they expected and leads Bailey to tell Meredith to end it. Alex treats a self-mutilation patient, while Izzie's patient literally won't let go of his girlfriend. Meanwhile, George is suspicious that an anesthesiologist is drinking on the job and Cristina fills ill with flu-like symptoms.

The interns treat a patient who, after a series of seizures, thinks he's gained psychic abilities. Meredith becomes dissatisfied with her relationship with Derek when she realizes that she knows nothing about his personal life. Alex treats a patient whose religion interferes with her recovery; Izzie debates whether or not to reconnect with her mother; and Cristina's patient disagrees with her medical advice.

When an STD breaks out, affecting several members of the staff, Webber calls a staff meeting. Later, the chief confides in Derek about his own medical concerns. Izzie and Cristina become stressed when a patient's wife and daughter can't decide on his care. Burke treats an old college friend, Bill, but his diagnosis creates questions about his wife. As Meredith and Derek continue to get closer, their relationship crashes down around them when a person from Derek's past shows up in his life.

See how it all began ...

Straight to the Heart re-examines the lives of the five interns and their past relationships, both personal and professional.

A one-hour special recaping the lives of the interns at Seattle Grace Hospital. Starting with their first day, the intern's lives, both personal and professional, are recapped, along with the struggles of their first year of being surgical interns.

While off from work, Meredith and Cristina discuss their mutual man problems and are interrupted when Joe, the bartender, collapses. While Webber recovers from his surgery, he appoints one of the surgeons as interim chief, but has George report to him all the happenings at the hospital. While Meredith learns more about Derek and Addison's past relationship, Cristina tries to decide what to do in her relationship with Burke.

A family arrives at Seattle Grace after a car accident. While treating the members of the family, Alex discovers that their problems are deeper than their injuries. Meanwhile, Mrs. Webber admits her marital worries to Richard as he recovers.

Meredith's secrets about the state of her mother, Ellis Grey, are revealed to the staff when Ellis is brought in for surgery. Meanwhile, secrets about Cristina's health are also revealed.

While trying to recover, Cristina proves to be a difficult patient, and matters are made worse when her mother visits. Ellis Grey, Meredith's mother also proves to be a difficult patient when she has the staff running in circles to please her. Derek and Meredith's relationship remains in limbo when Addison's departure is postponed when she becomes involved with the treatment of a cystic fibrosis patient.

Meredith and Derek have to use more than their medical knowledge when a woman's strictly religious father forbids her from having an operation that would save her life. Meanwhile, George and Alex are forced to perform a surgery in scarce conditions, and Derek is forced to decide between Addison and Meredith.

Meredith temporarily forgets her worries about Derek's decision when a train crash results in dozens of injuries. Later, Addison sees potential in Izzie, but Izzie is forced to choose between her friendship with Meredith or her career.

The entire staff is in awe when a patient, Shane, comes in with a hysterical pregnancy while Cristina, Izzie and Meredith aggressively work on his unique case. Meanwhile, Alex is encouraged to show his feelings for Izzie after treating a young, sheltered young patient.

Friends of Derek and Addison come to Seattle Grace for preemptive surgery to avoid breast and ovarian cancer. But the arrival of their friends tests Derek and Addison's professional relationship. Meanwhile, George treats a patient who fell five stories and is dissatisfied with his outcome and Cristina and Burke attempt a "normal" date.

Thanksgiving proves to be a difficult holiday for both the interns and residents. Izzie plans a big dinner, but it doesn't look like all the invited guests will show up. Meanwhile, George participates in the O'Malley turkey hunting tradition, which abruptly ends after a shooting accident and Meredith treats a comatose patient whose condition might be better than it appears.

Meredith is horrified when her one-night stand needs treatment after suffering from priapism. Meanwhile, Alex begins to frustrate Izzie and a pregnant woman carrying quintuplets stresses over her high-risk pregnancy.

Cristina finds little sympathy for an inmate who purposely endangers her health to get out of serving her term in solitary confinement. Meanwhile, the interns are put in charge of watching the newborn quintuplets, each with varying health concerns; Izzie's frustrations with Alex's shortcomings hit their end; and Derek teaches Izzie an important, yet painful lesson.

Burke and Cristina's differences are shown when a young boy needs a transplant but he refuses to get it. Meanwhile, the interns help Alex prepare for his exams when it's revealed that he failed them. Meredith has to re-instill the Christmas spirit in Izzie and Derek refuses to feel festive.

As the new year unfolds, Izzie vows to let Alex's affair go, and it comes easier when she hits it off with Denny Duquette, a heart transplant patient. George treats Bex, a teen hermaphrodite, with a tumor and Alex treats a man who ate his novel after not being pleased with the results. Meanwhile, Derek talks with Meredith's mom, Addison expresses her disgust with Derek's living arrangements, and the residents, especially Cristina, have a hard time dealing with the new work limit.

Cristina and Meredith hide the truth about their relationships from each other. George is assigned to discharge an elderly patient who refuses to leave; and Alex learns the fate of his career when the results from his medical exams come in.

When the nurses at Seattle Grace go on strike, the doctors are forced to work without them. While most of the doctors cross the picket line, George refuses to cross due to his union roots. With Bailey on maternity leave, the interns meet their temporary resident, Dr. Sydney Heron, who is the exact opposite of Dr. Bailey, which Cristina has a hard time adjusting to. Meanwhile, secrets from Izzie's past are revealed as she treats a young, pregnant teen; and Meredith makes a mistake in treating an elderly patient.

All morning, Meredith felt like she was in for a bad day. Her fears are realized when a medical case threatens the lives of everyone at Seattle Grace, causing officials to put the hospital on a "code black".

Despite the staff doing all they can, the potentially disastrous situation continues to escalate. Meredith begins to panic about her situation, as does Derek when he's told about her circumstances. Meanwhile, while the hospital is in chaos, Bailey and Webber have to deal with their own health issues.

When a person from Derek and Addison's past arrives at Seattle Grace, their now stable relationship is shaken up. Meanwhile, after visiting with her mother, Burke is told Cristina's secret; and after a visit with her mother, Meredith digs to find the family's secrets.

Meredith and George fight over who gets to treat a patient. Bailey, despite being on maternity leave, treats Addison for a specific feminine problem. Izzie starts spending time with Denny, and Alex becomes jealous. Meanwhile, Burke treats a man who had a heart attack, and the man's fiancée leaves him when she learns about the risky surgery he's decided to have.

Cristina has a hard day on the job when Bailey has her take care of her baby after she gets involved in a case, despite being on maternity leave. Meredith continues to deal with the fact that she slept with George, who begins to bond with Burke much to Cristina's disgust. Addison and Derek have a deep talk about their relationship and Denny continues to get in the way of Alex being closer to Izzie. Meanwhile, the interns must deal with a hockey player who wants an unnecessary amputation and a woman with a fork stuck in her neck.

The doctors' superstitious sides are brought out after several deaths and strange events take place at Seattle Grace. Derek and Addison talk about a more permanent living situation, Izzie worries about Denny's surgery, and Richard gets reacquainted with an old friend.

Derek performs brain surgery on Andrew, a young spelling bee champion who suffered a serious head injury. George, who begins to overstay is welcome at Burke's, has trouble not speaking up when one of his patients constantly lies about her health to her daughter. Bailey begins to worry that the interns will no longer see her as "the Nazi" now that she has a child. Meanwhile, Addison treats a patient with pregnancy issues; Alex gets a lesson in manners; and secrets are revealed about Meredith's father.

A strict Catholic mother of seven children comes to the hospital to ask Addison for medical help because her equally religious husband refuses to use condoms. Addison is able to come up with a solution to her problem, but Alex's interference causes problems for both Addison and the mother. Derek rethinks his marriage after treating a divorce attorney for seizures. Izzie hounds George for information about his private life and pressures him to move back into the house. Meanwhile, Meredith agrees to go out with Doc's vet and Burke is faced with considerable pressure when he has to operate on his musical hero.

The interns attend to Marshall, an intern from another hospital with short-term memory loss. Marshall was also the cause of a bad accident involving a family, which leads Derek to let his emotions get in the way of his work. Meanwhile, a woman from the past comes to visit one of the female interns, and Burke and Izzie have an idea relating to Denny's condition.

Finn continues to work with Doc and is able to give his owners, Meredith and Derek, and update on his condition. George is assigned to work with Derek, while Meredith is assigned to work with Callie. Denny still is without a heart donor, leaving Izzie and Burke to continue the hunt for a potential donor. Meanwhile, a 12-week pregnant woman dies in the O.R., and her parents' decision to try to keep the baby alive creates a rift between Addison and Derek.

George and Izzie race to find Denny a heart as his heart gets weaker and weaker by the minute. Derek is faced with the pressure of performing surgery on one of his friends, while Cristina is faced with the pressure of running the O.R. after she is left in charge. Meanwhile, the interns are supervised by Erica, a new attending, who tries her hardest to act like Bailey, but has a tough time doing so.

After Richard learns who Derek is operating on, he tries to pump Addison for information. Callie and George have a talk about their relationship and George's true feelings. Meanwhile, Meredith and Derek get together to talk about Doc, and later realize that their feelings for each other may not entirely be gone despite Finn being in Meredith's life and Addison being in Derek's.

In a clip-show, "Complications of the Heart" recaps the highlights of the previous season from the arrival of Addison to Meredith's cliff-hanging season finale scene. The episode will also feature the music video for The Fray’s single, “How to Save a Life" which features clips from season 2 as well as clips from the season 3 premiere.

"Every Moment Counts" recaps the events of the third season. Hosted by recurring guest star Jeffrey Dean Morgan (Denny Duquette), a montage of memorable scenes from the third season are shown as well as the premiere of an exclusive Grey's Anatomy music video set to Brandi Carlile's, "The Story."

In the fallout of Izzie's decision to quit the program, the interns try to help Izzie come to terms with the death of her fiancé, Denny. Meredith is forced to decide who will be the man in her future after her fling with Derek during the prom. Meanwhile, Dr. Webber is confronted by his wife after spending the night at the hospital; George asks an unlikely person for relationship advice; and Addison must find out which one of a group of teenaged girls is the mother of a baby found in a trashcan.

While Burke continues to recuperate in the hospital, his parents arrive at Seattle Grace to visit and end up meeting Cristina in embarrassing circumstances. The interns, as well as Bailey, lobby for Izzie to be re-admitted to the intern program. Meanwhile, Addison opts to take a day off from the hospital and spends the day at Joe's where she runs into both Izzie and a surprise visitor from her and Derek's past. Elsewhere at the hospital, a patient lives what she believes to be her last day to the fullest.

Finn and Derek continue to try to outdo one another in order to win Meredith's heart. Derek woos Meredith with once in a lifetime surgeries while Finn tries his hand at a romantic hospital date, all making it more difficult for Meredith to make a decision. With Burke's hand continuing to tremor, Cristina does her best to help him deal with his injury. As George and Callie's relationship continues to grow, Izzie attempts to visit the hospital for the first time since Denny's death. Meanwhile, Alex tends to a patient with numerous injuries.

As Addison works with Rebecca, a pregnant woman who needs to have a C-section but wants to give birth naturally, she begins to doubt her abilities as a doctor. The interns work with Shawn Sullivan, a car salesman who wants to return to his normal routine after he has surgery. However, when Shawn lights a cigarette that catches his face on fire, Derek and Mark argue over how they should procede with his burn treatment. Meanwhile, Burke continues to rehab his injured hands with the help of Cristina, gradually progressing from operating on chickens to operating on a corpse. Meredith goes into surgery after her appendix bursts and after surgery, she finally makes a decision between Derek and Finn. Elsewhere, Callie and George continue to discuss their relationship and Izzie meets a man who gives her the surprise of her life.

Bailey treats a young woman suffering from breast cancer while Derek begins to learn more about Addison and Mark's rekindled relationship. Meanwhile, the interns team up to defend a resident at a staff meeting, and Meredith and Addison stumble into an awkward situation with one another.

Cristina gets the once in a lifetime opportunity to scrub in on a rare humpty-dumpty procedure, much to the envy of the other interns. Meanwhile, Alex begins to question his choice of surgical specialty and George and Addison work together to help Noelle, a woman pregnant with twins that are developing at different rates.

The Seattle Grace men pack up and head out to the Seattle wilderness for a camping trip. Back at the hospital, Callie and Addison work together on a pregnant patient who slipped and broke her arm in the shower and Meredith helps Dr. Sloan with a unique sex reassignment surgery. Meanwhile, Bailey becomes increasingly suspicious of Cristina and Burke and decides to confront Cristina. Elsewhere, the interns treat a 9 year-old who swallowed Monopoly game pieces.

George's family comes to Seattle Grace when George's father hurts his clavicle, throwing George into a frenzy. However, George's worst fears about his father's hospital visit are realized when the test results come back abnormal. As Meredith strives to have a more positive outlook on life, Derek and Addison work on finding away to have a civil relationship once again. Meanwhile, Richard attempts to work things out between him and Adele.

The ER is taken over by a horrific car accident and the trauma caused by the accident pushes and challenges the interns. Elsewhere, Cristina begins to wonder if she's doing the right thing by helping Burke lie about his hand condition and Izzie pushes the boundaries of her probation.

Burke and Cristina's relationship continues to be strained in the aftermath of Cristina revealing Burke's limitations due to the shooting. Meredith's half-sister, Molly Thompson, is admitted to Seattle Grace forcing Meredith to once again confront her emotions towards her father and sister. Meanwhile, Derek and Mark are forced to work together when two conjoined brothers come to the hospital to be separated.

After George's father's heart operation, Mr. O'Malley heads back to the O.R. for another surgery for his cancer. As George continues to worry about his father, Meredith's father visits Seattle Grace in order to see his newborn granddaughter. Meanwhile, Meredith discovers that Derek is having trouble sleeping, which is no fault but her own. Elsewhere, the interns treat an angry 17 year-old girl with severe scoliosis who has a poor attitude towards the doctors due to the several surgeries she has endured during her life.

Mr. O'Malley heads back to surgery in order for the doctors to operate on his cancer. Meredith deals with her emotions while her father is at Seattle Grace to visit his new granddaughter. Meanwhile, a woman has a breakdown at the hospital after having to give up something important to her. Elsewhere, Meredith continues to worry about Derek when he is unable to sleep.

While rumors about the chief's retirement begin to fly among the hospital staff, Bailey pushes for the creation of a free clinic at Seattle Grace. George uses sex as a way to cope with the death of his father, which worries both Izzie and Callie. Meanwhile, The interns treat a woman diagnosed with stage 4 cancer who has a complex Puritan past and Callie and Cristina operate on a runner in order to save his legs. Later, one of the doctors receives a surprising proposal.

With Izzie's inheritance money, Bailey and Izzie open the Seattle Grace free clinic and eagerly wait for their first patient. The lives of the doctors are put at risk when a patient's blood is found to be toxic. Meredith, Cristina and Izzie volunteer to risk their lives to save the woman after Derek and Burke's air-tight suits run out of battery. Meanwhile, Ellis, Meredith's Alzheimer's-stricken mother, has a change in her condition; George and Callie return to the hospital with surprising news; and Cristina gives Burke an answer to his proposal.

A horrific ferry boat accident challenges the interns, as well as the rest of the hospital staff, both physically and mentally as they all near their breaking point. Chief Webber has to assemble and send out a team to the location of the accident to help save the few lives that were spared. On location, Alex tends to a woman who was crushed by a cement pylon. Meanwhile, Meredith looks out for a lost young girl and George searches frantically for a woman's young son.

As the chaos surrounding the ferry boat accident continues, Derek frantically searches for Meredith, and is devastated when he finds her barely clinging to life. Cristina is also devastated when she learns about Meredith's condition. Meanwhile, emotions run high at Seattle Grace as family of the accident victims demand to know the status of their loved ones. In the midst of the trauma, Alex has trouble dealing with the death surrounding him; George searches for a missing 7 year-old boy; and Izzie is forced to take desperate measures to save the life of the man stuck under a car.

While Meredith's life hangs in the balance, the interns each have to grapple with the reality that she may not make it. Derek refuses to give up hope that Meredith will pull through, but as time passes, Derek begins to slowly break down. Cristina takes the possibility of her death the hardest, and refuses to accept that it could happen. As Bailey and Chief Webber work to save Meredith's life, Meredith is visited by figures from her past, including Denny and Dylan Young, both of whom try to convince her not to die. Elsewhere, Addison and Alex continue to work with their pregnant Jane Doe, who has no memory of the ferry boat accident or her life prior it.

The race for Chief of Surgery continues to heat up, especially when a new contender enters the race. Callie reveals a big secret to George, and when George ends up telling Meredith, Callie kicks him out, leaving George with no where to go except to Meredith's. Cristina and Burke's engagement suffers when a secret about one of Cristina's past relationships is revealed. Meanwhile, Derek treats an old friend; Alex and Jane Doe get closer; and Meredith has dinner with her father and step-mother.

George comes face-to-face with his father-in-law, but the circumstances of their meeting are less than perfect. Alex continues to tend to Jane Doe and helps her choose how the world will see her from here on. Meanwhile, the board interviews Chief of Surgery candidates, and everyone is stunned when Sloan emerges as a top candidate. Elsewhere, Izzie wrestles with the events of her drunken night with George.

When Izzie has to face her past, she turns to George for support and comfort. As Alex continues to work with Jane Doe, the two become more attached to each other. Meanwhile, Meredith and Derek begin to question their status while Cristina strives to repair her relationship with Burke despite her past history with Dr. Marlow that continues to damage their engagement.

As the interns study for and stress over their upcoming exam, the attendings suck up to the chairman of the board in order to become front runner for the Chief's position when he is admitted to the hospital as a patient. Meanwhile, Burke has a difficult time involving Cristina in the planning of their wedding, Addison and Alex get closer, and Derek begins to second guess his relationship with Meredith.

Addison, on leave from Seattle Grace, heads to Los Angeles to reconnect with old friends from med school. Back in Seattle, Meredith continues to bond with Susan, her step-mother, and Cristina, with the help of both her mother and Burke's mother, begins planning her wedding. Meanwhile, Derek performs emergency surgery on Ava (Jane Doe) and Alex continues to stand by her.

In the conclusion to part 1, Addison visits Los Angeles and continues to reconnect with her old medical school friends. In Seattle, Meredith gets closer to her step mother. Cristina deals with the pressures of her pending marriage, and reluctantly plans the wedding with her mother and future mother-in-law. Meanwhile, Derek operates on Ava.

The interns face one of their biggest challenges yet -- their first-year medical exams. Meanwhile, the interns must tend to three injured mountain climbers. Elsewhere, Callie becomes increasingly suspicious of George and Izzie and Cristina has trouble writing her vows.

A big day arrives for all -- Cristina and Burke's wedding and the interns receive their exam results. Meanwhile, Chief Webber's replacement is named and George and Callie make a decision about their relationship.

"Come Rain or Shine: From Grey's Anatomy to Private Practice" goes into the life of Dr. Addison Montgomery as she transitions from Seattle Grace to Oceanside in the new spin-off Private Practice. The episode also includes the premiere of the Grey's Anatomy music video featuring "Breath In Breath Out," a song by Mat Kearney. The video features clips from the previous three seasons and the episode will feature a glimpse at the new season of Grey's Anatomy.

Meredith and Cristina return from Cristina's honeymoon to find that Burke is long gone. Izzie, Alex, Meredith and Cristina start their first day as residents, each with their own set of interns. Among the interns are George, who is repeating his internship after failing the exam, and Lexie, Meredith's half-sister. Meanwhile, Derek begins to look elsewhere after his relationship with Meredith hits an emotional impasse; Bailey grapples with the fact that her former interns now report to Callie, the new Chief Resident; and Richard returns to his position as Chief of Surgery.

The interns and residents treat victims of an apartment complex explosion as Alex looks into the cause of the devastating accident. Mama Burke arrives at Seattle Grace to pick up the rest of Burke's personal things while Cristina trades wedding gifts for surgeries. Meanwhile, Lexie tries to talk to Meredith, who is less than willing to do so; Callie deals with the stress of being Chief Resident; and Bailey tries to figure out what to do with her excess leadership skills.

The new interns are in awe of fellow intern George's skill level, and Lexie tries to keep his "repeater" status secret. Meredith comes to Lexie's aide when Lexie is faced with her first emergency situation. The Chief and Sloan have to use a radical surgery to save a woman's vocal ability. Meanwhile, George debates telling Callie about his affair with Izzie.

Izzie reveals her true feelings for George to one of her and George's friends, and the reaction she receives is not what she expected. Meanwhile, Adele Webber rushes her niece to Seattle Grace; Derek gives Cristina pointers on how to be a better teaching resident; and Norman, the world's oldest intern, misdiagnoses Meredith's patient.

It's Halloween at Seattle Grace and the day is chock-full of surprises for the doctors. Alex has a surprise visit from a former patient; Meredith thinks her mother's ashes are haunting her; Cristina is snubbed by a top surgeon; and everyone is shocked when Callie reveals George and Izzie's relationship to the public.

With his marriage once again falling apart, Chief Webber invites the male surgeons out on a "gentleman's evening." Meanwhile, Cristina and Izzie compete for the same surgeries, mainly to impress the doctor performing them; Meredith treats the survivor of a skydiving accident; and two finalists competing in a promotional competition are treated by the doctors.

George and Izzie's relationship is tested, as is Derek and Meredith's when Derek wants more than a physical relationship with her. Meanwhile, Mark falls for a surgeon and Callie's position as Chief Resident is put on the line when she gives too many duties to Bailey.

The ER is thrown into a state of chaos following a school bus accident. Meanwhile, Bailey treats her high school crush; Derek goes on a date; and Thatcher comes to Seattle Grace in search of Meredith.

Meredith and the Chief rush to the scene of a devastating ambulance crash in which the lives of the paramedics are at stake. Bailey treats a difficult patient and Ava returns to find Alex with a new girlfriend.

In the conclusion to the two-part episode arc, Meredith races to save the life of a paramedic, who is trapped inside an ambulance. Meanwhile, the life of a patient is in Lexie's hands and Derek and a nurse work together to save the life of a patient.

Bailey's family faces a medical trauma, just as her marriage is falling apart, a surprise visit from George's mother comes as a shock to both Izzie and Callie, a faith healer challenges Erica and Alex's beliefs in traditional medicine, and Derek must deal with the aftermath of his kiss with Rose.

Six weeks following Derek and Meredith's break-up, Derek continues to date Rose while Meredith, Alex, Izzie and Cristina compete in a surgical contest. Meanwhile, George and Lexie adjust to their new apartment and Callie finds a new friend in Erica Hahn.

Addison makes her return to Seattle Grace in order to perform an operation. As she does so, she is preoccupied by all of the changes in her former co-workers' lives. Meanwhile, Meredith and Derek's clinical trial has its first patient, and Rebecca returns to deliver Alex some shocking news.

The nurses' outcry over McSteamy's frequent trysts leads the hospital to enact a new "date and tell" policy. Meanwhile, news about Burke's career force Cristina to cope with her feelings about the past; Meredith and Derek take in a veteran soldier to participate in their clinical trial; and Callie finds comfort in Sloane when she needs it the most.

As Dr. Wyatt refuses to let Meredith give up on her therapy sessons, Alex learns the truth about Rebecca's condition. Chief Webber has Dr. Hahn perform a high-risk surgery on his mentor. Meanwhile, after hearing about Burke, Cristina continues to act unusually, going as far as to clean her ever-messy apartment.

In the two-part season finale, Meredith and Derek take another shot at the clinical trial while the others race to free a boy from a hardening block of cement. Meanwhile, Izzie helps Alex care for Rebecca and Lexie learns a secret about George's intern status.

In the two-part season finale, Meredith and Derek take another shot at the clinical trial while the others race to free a boy from a hardening block of cement. Meanwhile, Izzie helps Alex care for Rebecca and Lexie learns a secret about George's intern status.

As Meredith and Derek begin to find that their "happily ever after" is anything but easy, Cristina develops a crush on a military doctor who brings in a trauma patient. Meanwhile, the Chief and his staff cope with the news that Seattle Grace is no longer considered a top-tier teaching hospital.

While Meredith and Derek continue in their new relationship, Cristina continues to get to know the military doctor as they treat his trauma patient.

When the plumbing springs a leak, chaos breaks out at Seattle Grace as the Chief tries to put in place new teaching methods. Meanwhile, George takes his residency exam; and Derek attempts to get Meredith's roommates to move out, much to their surprise.

Meredith is sent into a state of panic when Derek finds her mother's diary in the house. Meanwhile, Callie stresses while preparing for her first date with Erica. Later, Cristina stumbles across a part of the hospital no one has ever seen before.

Bailey leads a team for a "domino procedure" in which each surgery is dependent on the one before it. Meanwhile, Derek receives sole credit for the study he and Meredith worked on; Lexie tries to get George to see her in a different light; and Sloan gives Callie relationship advice.

The Chief gives Bailey new responsibility in order to help her to be one of the best surgeons at Seattle Grace. Meanwhile, Owen Hunt, the new head of trauma, clashes with the current staff's methods and abilities.

When the Chief makes an announcement that a solo surgery is up as an award, the residents are sent into a frenzy all trying to get an edge over one another. Meanwhile, Derek asks Bailey for advice after Cristina continues to interfere in his relationship with Meredith. Elsewhere, Erica uncovers a shocking connection between a resident and a patient.

Sadie, one of Meredith's oldest friends, is brought on as an intern at Seattle Grace; however, Meredith's friends are less than welcoming to her. Meanwhile, Lexie leads the interns on a unique training session; and Virginia, a new surgeon, brings new rules to the O.R.

Meredith, Cristina and Bailey must save Lexie and Sadie after a routine surgery goes terribly awry. Meanwhile, Owen and Derek treat a man injured while sleepwalking.

Cristina wins the first solo surgery among the residents, but is forced to give it up and choose who will perform the surgery in her place. Meanwhile, Mark heads up a procedure that will allow his patient to regain their ability to speak. Elsewhere, Callie tries to figure out if Sadie is being friendly to her or hitting on her.

Bailey pairs up with Dr. Arizona Robbins, Seattle Grace's new pediatric surgeon, to help save the life of a young patient. Derek is furious when a death row inmate is checked in to the hospital; Cristina and Meredith's friendship continues to erode; Callie and Sloan work through their attractions to Sadie and Lexie; and Izzie confesses to Alex that she has been seeing Denny.

Derek's mother, Carolyn, makes a surprise visit and meets Meredith for the first time. Meanwhile, Mark tries to hide his relationship with Lexie; William, the death row inmate, asks to donate his organs to Bailey's patient; and Owen and Cristina go on their first date.

Bailey becomes desperate as her patient's condition rapidly worsens, causing everyone to work to find the boy an organ donor before it's too late. Meanwhile, Mark finds himself in a compromising position and Crisitina avoids Owen.

With the engagement ring taken care of, Derek ponders the perfect way to pop the question to Meredith. Meanwhile, Lexie demands that Mark go public with their relationship; and Bailey, happy with her work with recent patients, considers a new career direction.

Addison, Naomi and Sam bring Archer to Seattle Grace in order to have Derek and Mark work to save his life. Meanwhile, Izzie works on a medical game to help the interns.

Derek's confidence is dashed as he squares off with Addison over a patient. Cristina begins to doubt the abilities of a surgeon after she messes up on a routine procedure. Meanwhile, Bailey, pursuing a fellowship in pediatrics, is appalled by the Chief's recommendation letter.

When Derek learns that more of his patients have died than survived, he decides to quit despite Meredith standing by him. Meanwhile, Bailey and the Chief continue to fail to see eye-to-eye on the fellowship until Adele steps in. Elsewhere, Izzie's interns discover dire news in regards to "patient x," unaware it's Izzie.

As Izzie continues to hide her medical secret, the residents all try to convince Derek to come back to work but fail at doing so. Meanwhile, Mark attempts a radical face transplant surgery; and Cristina is awarded a solo surgery, but is preoccupied by Izzie's condition.

Tensions are high as Derek returns to Seattle Grace to perform his first surgery following his breakdown. Meanwhile, everyone turns their attention to Izzie, who must undergo surgery for her condition; and Owen suffers from another PTSD episode that injures Cristina, putting their relationship at risk.

As she endures aggressive treatment for her cancer, Izzie throws herself into planning Derek and Meredith's wedding.

As Meredith and Derek continue to prepare for their wedding day, Izzie receives a surprise visit from her mother, and a person from Meredith and Lexie's past arrives at Seattle Grace.

As Meredith, Derek and their friends and family gather for their wedding, a group of several college students are admitted to the E.R. following a car crash.

After spending time with a fellow cancer patient, Izzie begins to question whether or not to undergo a risky procedure. Meanwhile, Mark considers taking his relationship with Lexie to the next level; and after helping a patient, Owen begins to rethink his position at Seattle Grace.

George gives Bailey news that shocks the entire hospital as everyone awaits for Izzie to recover from surgery. Meanwhile, Bailey is accepted into the pediatric fellowship program; and Seattle Grace comes together to help save a traffic accident victim.

The Seattle Grace staff has to deal with the aftermath of George's tragic death. As the news hits the staff hard, they all must find a way to get through the stages of grief. Later, George's mother arrives at the hospital to decide what to do with his organs.

Though time has passed since George's death, everyone continues to struggle with his passing by finding distractions to keep themselves occupied. Meredith and Derek cope by consummating their marriage anywhere and everywhere, while Dr. Wyatt suggests that Cristina and Owen abstain from sex.

Izzie returns to work following her near-death experience. Meanwhile, the Seattle Grace residents brace for upcoming layoffs and try to position themselves in order to keep their jobs, with Cristina attempting to work with Arizona in pediatrics. Elsewhere, Bailey and Alex's complex case becomes increasingly difficult when the patient's schizophrenic son has issues with her care.

Thatcher returns to the hospital in need of a new liver, and Meredith is the only one who is a match leaving her to make a tough decision. Meanwhile, Izzie finds common ground with a patient with tumors; and Mark, annoyed with Cristina, has her assist on an unusual surgery.

Seattle Grace and Mercy West residents compete for surgeries as the two hospitals are merged. Meanwhile, Arizona stands by Callie when Callie's father brings in a priest in hopes of convincing her to stop dating women.

When a burn victim unexpectedly dies during a chaotic time in the emergency room, the Chief, with the help of board member Jennings, interview each of the residents in order to find who was to blame in the incident, leading each of the doctors to defend their actions of the day to save their jobs.

When Isaac, the hospital lab tech discovers he has an inoperable tumor wrapped around his spine, he seeks Derek for help. Meanwhile, Richard's authority is challenged by Derek.

The parents of Arizona's young patient offer the hospital a sizeable donation, but when the patient takes a turn for the worse, Arizona finds herself torn between the hospital and the patient. Meanwhile, Cristina tests her boundaries with Owen.

Owen recruits a new cardiothoracic surgeon, Iraqi War vet Dr. Teddy Altman, but Cristina is quick to judge her abilities in the O.R. Meanwhile, Izzie returns to Seattle Grace with her former high school teacher who is suffering from dementia; and the Chief begins to feel the strain of his new responsibilities post-merger.

As the holidays come and go, Miranda has a surprise visit from her father, William, who has a strong disapproval of her choices in life. Mark and Lexie must cope with a person who re-enters Mark's life, and Thatcher Grey questions the Chief's behavior, but Meredith is quick to come to the Chief's defense.

Mark flies Addison to Seattle so that she can help perform a difficult procedure on his pregnant daughter. Meanwhile, Owen begins to question Teddy's motives when she has Cristina be the lead on a complex surgery; and Derek becomes suspicious when the Chief has Meredith assist on a high-profile operation.

Derek confronts Richard over his alcoholism in an attempt to help his friend and the hospital. Izzie returns to reconcile with Alex, and tensions between Teddy, Cristina and Owen escalate.

After being named interim chief, Derek begins to settle into his new position but faces a lawsuit when Bailey and Meredith's patient wakes up during surgery. Meanwhile, Teddy refuses to let Cristina be a part of her service, Alex continues to work with Arizona in pediatrics, and Mark avoids talking to Lexie who is still heartbroken over their break up.

The doctors treat dozens of people when the roof of a romantic restaurant collapses on Valentine's Day, Meredith struggles with her new duties as the chief's wife.

Source: ABC

Callie, Bailey and Richard present pivotal surgical cases from their pasts when Derek restores the hospital lecture series.

Source: ABC

When famous surgeon Dr. Harper Avery is rushed to Seattle Grace-Mercy West, the staff is surprised to discover that one of their own is related to this legend, and his unorthodox request for his surgery causes tensions t between Derek and Richard. Meanwhile Callie and Arizona try to help Teddy and Sloan move on from their pasts and find greener pastures.

Source: ABC

A patient who needs an extremely difficult surgery comes to Seattle Grace, and it's Richard and Owen who vie for the opportunity to tackle it. But the decision lies in the hands of Derek, who deems that Owen should take on the surgery, leaving Richard bitter. Meanwhile, Bailey deals with her own personal struggles when she nervously prepares for another date with Ben.

When Teddy's patient seeks to end treatment and her life, she turns to Hunt for help. The situation triggers Hunt's memories of his life at war and his past relationship with Teddy. Meanwhile, Callie and Arizona have a difference in opinion on what their future holds, and Richard tries to adjust to his role as a surgeon.

When Alex's brother shows up at the hospital with a hernia, Alex must get Bailey's approval for pro-bono surgery; parts of Alex's past are revealed to his friends and colleagues.

Source: ABC

Sloan returns to Mark's apartment, just as she's going into labor, and Teddy, Mark and the still-fighting Callie and Arizona are there to help with the birth and to get Mark through his grandson's pending adoption. Meanwhile Teddy sees Derek's invitation to illustrious cardiothoracic surgeon Tom Evans' as a threat to her future employment at the hospital, and the team work on a crab boat captain who has been stabbed with a giant shark hook

Source: ABC

Bailey preps the team with mandatory sensitivity training prior to admitting a 700-pound patient with compounded medical issues, and the case proves to be challenging in every sense of the word. Meanwhile Derek has to come face to face with a former patient's husband in a wrongful death deposition, and spending time with a heart patient's daughter opens up some old wounds for Cristina,




Source: ABC

An elderly patient admitted into the E.R. for a heart condition sees a familiar face, a long lost love who happens to be in the E.R. as well for a fractured arm, and the staff find themselves caught up in their love story. Meanwhile, Karev treats a troubled teenage patient whose parents brought her in for schizophrenia, and Meredith can't help but tell Cristina about her suspicions of Owen

Source: ABC

The hospital is hit with an unprecedented crisis; Meredith and Cristina's surgical skills are put to the test.

Source: ABC

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The hospital staff is trying to deal with physical and emotional trauma in the wake of the deadly rampage of a vengeful gunman. As Dr. Perkins, a trauma counselor, is brought in to help in the recovery and to assess each doctor’s readiness to return to work, Derek makes a spontaneous decision to resign as Chief and rushes back into surgery, taking everything a little too fast, and Cristina buries herself in her wedding planning.

Source: abc

After weeks of concealing the fact she was pregnant and miscarried, Meredith at last tells Derek and is finally cleared to return to her surgical duties in the wake of the hospital shooting spree; Cristina experiences post-traumatic stress disorder in the midst of an operation; and Bailey refuses to let Alex operate until he agrees to have the bullet in his chest removed.

Source: ABC Publicity

When Derek receives an unexpected and unwelcome visit from his estranged sister, Amelia, issues between the siblings -- both past and present -- come to the surface; the Chief tries to help Alex when he notices that he's refusing to use the elevators after his near-fatal shooting; and Meredith and Derek continue their efforts to ease Cristina back into surgery after her post-traumatic stress

Source: ABC

Things are hostile on all fronts when a visit to the obstetrician results in some disturbing news for Meredith and Derek, and Lexie loses it when she notices Meredith and April getting closer. Meanwhile a car crash brings in multiple traumas and Jackson tries using his physical attributes to get ahead in the operating room, while Cristina's self-doubt carries outside of the hospital and into her house hunting with Owen

Source: ABC

As part of their training, the Chief puts Seattle Grace's residents, including Meredith, Cristina, April and Jackson, in charge; meanwhile, Derek, Callie, Owen and the other attending surgeons compete for a million-dollar grant

Source: ABC

A documentary film crew visits the hospital six months after the shooting to document the road to recovery for doctors and patients. The camera lenses follow Derek, Owen, Mark & Callie as they ambitiously perform a rare arm transplant surgery, Meredith helps Cristina put on a brave face for the cameras, and Bailey's patient, Mary, returns for her surgery -- which marks the first time they've all seen of each other since that fateful day

Source: ABC

The residents are pushed to their limits when Owen puts them through a rigorous trauma certification drill; meanwhile, Cristina is also tested when left alone to monitor a very ill lung transplant patient

Source: ABC

Top security measures go into place as a team of doctors, led by the Chief, try to save the life of a major policitcal figure from the Middle East. Meanwhile Cristina decides to finally decorate her new place and throw a housewarming party, and Alex shows up late from a weekend getaway to his first day of rounds with the new Pediatrics Attending, Dr. Phil Stark.

Source: ABC

Derek lands the grant he needs for his clinical trial and all the attendings take him out to Joe's Bar to celebrate, but they get a surprise when they see someone they know already at the bar. Meanwhile, Meredith and Alex have to fend for themselves during the night shift with a nine-year-old patient who's experiencing post-surgical complications and his very pushy mother.

Source: ABC

Despite Meredith's objections to the idea, a concerned Derek takes Cristina on a fishing trip in order to get away from it all, while Teddy, feeling directionless without Cristina, directs all of her efforts and compassion towards a dying patient who lacks the proper insurance to seek medical treatment.

Source: ABC

News of the incoming mass causalities after a gunman opens fire at a local college hits the staff hard when they must spring into action, even while their own wounds are still fresh; and Arizona does not receive a warm welcome home at the hospital.

Source: ABC

Arizona seeks Mark's advice as she tries to reconcile with Callie, who has big news of her own; Teddy must make a key decision for Henry during his surgery; and on the same day the residents receive a new crop of interns, the Chief announces he is looking for a new Chief Resident.

Source: ABC

Derek begins a clinical trial for an Alzheimer's therapy. Friction arises when he chooses to exclude Meredith from assisting with this research. Bailey uses Twitter to describe an abdominal surgery, provoking the Chief's ire - until the feed creates a degree of collaboration that spares a patient from a lifetime of serious diabetes following a pancreatectomy. Callie's concern over her perfectly normal pregancy symptoms drive new obstetrician Lucy Fields, Mark and Arizona to distraction.

Thatcher Grey, Meredith and Lexie's father, returns to Seattle Grace with stomach pains and a new, twenty-something tattooed girlfriend, Danielle. Meanwhile, Alex clashes with the new OB, Dr. Lucy Fields, over a patient and Mark places Jackson on his service in exchange for information on Lexie.

Source: ABC

Meredith, looking to prove she is Chief Resident material, learns that anything and everything can happen in an hour's time when she steps up to run the ER for a night; meanwhile, Bailey sneaks off with Eli and gets into a little mischief, and everyone is surprised when the Chief's wife, Adele, shows up as one of the ER patients.C

Source: ABC

Meredith must choose between her fertility treatments and her eyesight when she begins having trouble seeing, Mark makes it clear to Callie and Arizona that he takes his role as father-to-be very seriously, and April discovers there's more to Dr. Stark than first appears.

Source: ABC

Richard is desperate for Derek and Meredith to accept Adele into their Alzheimer's trial, but will Adele stand in her own way? Meanwhile Mark and Arizona have conflicting ideas of the kind of baby shower Callie wants, Teddy is freaked out when Henry has another health complication -- leaving them both a little exposed -- and the competitiveness amongst the residents for the Chief Resident position is amplified when Richard receives the green light for his diabetes clinical trial.

Source: ABC

Callie and Arizona are rushed back to Seattle Grace Mercy West Hospital after a car accident, where Callie is in critical condition. The doctors must act quickly to save both Callie and her unborn baby, while tensions between Mark and Arizona rise. The episode is done as a musical, using various top-40 hits, with the words being sung by the characters.

Everyone pulls together to help Callie and baby Sofia on their painstaking journeys to recovery in hopes of allowing mother and baby to finally meet; the sudden death of a clinical trial patient has Derek proceeding with more caution while Meredith makes a calculated and risky move; Alex treats a cranky old rich woman dying of cancer and gets an idea for a grandiose endeavor that is sure to get him the Chief Resident spot; and Teddy is pleasantly surprised by the return of a familiar face.

Source: ABC

As Callie and Arizona's wedding approaches, the couple quickly realize that the day they've been looking forward to is not turning out the way they'd envisioned. Meanwhile Alex continues to make the other residents jealous as he appears to be the top contender for Chief Resident, Meredith and Derek make a decision that will change their lives forever, and Dr. Perkins presents Teddy with a very tempting proposition.

Source: ABC

Personal and work pressures are adding up and have Meredith visibly on edge, Owen conducts formal interviews for the Chief Resident position, Cristina grows increasingly defiant, Alex and Lucy's undefined relationship gets tested, and Jackson suddenly backs out of the Webber's diabetes trial.

Source: ABC

News of Meredith's dishonesty in the clinical trial comes to light, leading to unanticipated consequences for both her and others. Cristina finds herself in a compromising situation, which forces her to decide between her career and her relationship. Meanwhile, Owen posts his decision for chief resident and Teddy makes a surprising choice regarding her love life -- and her future.

Source: ABC

The fifth-year residents return for the first day of a year that will make or break their careers: Meredith faces the consequences of tampering with Derek's clinical trial and is terminated at the hospital; April tries to step up to the plate as Chief Resident in the wake of a giant sinkhole in the middle of Seattle; and Cristina and Owen are still at odds over their drastically different feelings for their unborn child.

Source: ABC

News of Meredith and Derek's unsteady relationship raises a red flag for Zola's adoption counselor; Alex quickly realizes that he has become the outcast of the group after ratting out Meredith; and Cristina makes a tough decision regarding her unexpected pregnancy. Also, Chief Webber brings Henry in for a last minute surgery, alarming Teddy.

Source: ABC

The Chief makes a career-changing decision that shocks Seattle Grace Hospital; Cristina and Owen try to find normalcy in their relationship; April continues to struggle in her new role; and the 5th year residents are given their first solo surgeries, only to find out that even the most routine procedures aren't always easy.

Source: ABC

The doctors of Seattle Grace are called upon to man up when a stampede at a comic book convention causes an influx of colorful characters in the ER - blurring the lines of fantasy and reality; Mark shows his softer side with baby Sofia when Arizona and Callie go out of town, but at work he continues to give Jackson a hard time; Ben returns to the ER, only to find that Nurse Eli has moved in on Bailey; and the male doctors bond over their frustrations with women.

Source: ABC

The residents try their hardest to impress surgical great Catherine Avery (who also happens to be Jackson's mother) when she arrives at Seattle Grace to perform a groundbreaking transplant surgery; Arizona and Alex find their hands tied with a confidentiality issue when a familiar patient comes into the ER; meanwhile, a love-struck Teddy throws a dinner party for the couples, and Bailey makes a decision regarding her love life.

Source: ABC

After being blackballed by most of the surgeons, Meredith uses Lexie to spark Derek's interest in her patient's rare brain tumor case and, in secret, gives guidance to April with Bailey's clinical trial; Callie's wish for Arizona and Mark to form a friendship comes to fruition and she realizes it's more irritating than helpful; Alex and Teddy research alternative surgeries for a very superficial patient; and Callie and Cristina struggle with a very difficult spinal surgery.

Source: ABC

Owen stresses teamwork and moves his leadership role over to the baseball field when he signs the doctors up for a baseball league, pitting them against their biggest competition, Seattle Presbyterian; Lexie tries to hide her jealous rage when she sees Mark with a new woman, but her emotions get the better of her; Alex fights to keep Zola at Seattle Grace after it is suggested that she be moved to another hospital due to a conflict of interest with Meredith and Derek; and Richard scolds Meredith and Bailey for their feud.

Source: ABC

The doctors become nostalgic when George O'Malley's mother, Louise, returns to Seattle Grace for medical help after a botched surgery at a neighboring hospital; the residents are inspired by a medical miracle when they witness a harvested heart that continues to beat outside the body; a new pediatric fellow excites Arizona and makes Alex feel threatened; Jackson lets his suspicions about Mark and Lexie interfere with his work; and Henry and Teddy have their first marital fight when he expresses interest in pursuing medical school.

Source: ABC

Teddy puts her husband’s life in the hands of her peers when Henry is sent to the OR for surgery and she’s called away on another case; Meredith and Derek receive the long-awaited news about Zola; Callie and Jackson come under fire when their patient experiences post-surgery complications; and Meredith and Alex are involved in a life-threatening situation when they travel to a neighboring hospital to tend to a sick newborn.

A severe car crash involving an entire family results in an all-hands-on situation in the ER, as the eldest daughter is left to make the toughest decision of her life. Meanwhile Teddy, still in the dark about Henry's death, calls upon Cristina to help with her patient in the O.R., and Lexie finds herself working alongside Mark's new girlfriend, Julia, during an eye surgery.

Source: ABC

The doctors split into teams for a risky surgery involving conjoined twins; Bailey recruits Meredith to be a buffer between her and Ben when he puts pressure on moving their relationship to a more serious level; Richard teaches Alex a tough lesson in the OR; meanwhile Teddy questions Cristina about what exactly happened to Henry during his surgery.

Source: ABC

Richard performs his 10,000th surgery on a pair of bickering sisters who come into the hospital for a liver transplant; Derek and Lexie take on a neuroblastoma case that has been previously deemed inoperable; Teddy and Cristina cross the line when they go against Owen's orders and try to steal a case from Alex and Dr. McQueen; Ellis Grey's shadow looms as Meredith searches for a specialty; meanwhile Adele is brought into the hospital after she is found wandering the streets.

Source: ABC

As Meredith puts Zola to bed and falls asleep, she begins to wonder -- what if her mother had never had Alzheimer's and she'd had loving, supportive parents? The reverberations of a happy Meredith Grey change the world of Seattle Grace as we know it. What if she had never met Derek in that bar and he had never separated from Addison? What if Callie and Owen had become a couple long before she met Arizona? And what if Bailey never evolved from the meek intern she once was?

Source: ABC

In the spirit of Valentine's Day, Meredith and Derek try to have a night to themselves when Lexie offers to watch Zola; Callie hands babysitting duties over to Mark so that she can surprise Arizona with a romantic evening; and Ben proves to Bailey that he knows her better than she thinks. Meanwhile, the ER fills with romantics, including a 10-year-old girl who has an allergic reaction to chocolates from her valentine and a man who is hit by a car while chasing down his frustrated girlfriend.

Source: ABC

In a final attempt to save Erica's life, Amelia arrives at Seattle Grace to beg Derek for help with the gliosarcoma case; Cristina and Owen engage in heated arguments during marriage counseling; Alex realizes that in order to be a good doctor, he'll need to improve his people skills; and Meredith is given a chance to shine when a man enters the ER after getting his hand stuck in meat grinder. Meanwhile, the residents continue to study for their upcoming oral boards.

Source: ABC

As Adele's condition continues to deteriorate, Richard considers altering their living situation; an explosion at a local coffee shop results in a busy day in the ER for the doctors; Callie takes Meredith under her wing by helping her study for her boards; Lexie joins Arizona and Alex in peds, as they continue to care for intern Morgan's premature son; and when Jackson snaps at a patient, Mark encourages him to find ways to relieve his stress. Meanwhile, Cristina lets her suspicions get the best of her.

Source: ABC

Derek encourages a hesitant Meredith to work with him again in neurology; Jackson's mother, Catherine Avery, returns to Seattle Grace with a urology fellow and develops an interest in Richard; and Cristina becomes increasingly suspicious of Owen's every move. Meanwhile, Alex tries to deny the fact that Morgan may be falling for him.

A lion breaks loose in Seattle, leaving a couple's lives and relationship at risk; Lexie overhears Mark's discussion about moving in with Julia; Teddy begins to take steps towards coming to terms with Henry's death; Callie grills Arizona on her past lovers; and Alex requests to be taken off Morgan's preemie case when she becomes too dependent on him. Meanwhile, Meredith tries to be a support for Cristina as the tension between her and Owen hits a boiling point.

A devastated Cristina presses Owen to confess the intimate details of his affair; Mark takes his new authority very seriously when he steps in as chief for the day and butts heads with Richard over a patient's liver transplant; and Callie deems Meredith ready for the boards, while the rest of the residents continue to stress about the exam. Meanwhile, Callie, Arizona and Bailey plan a much needed ladies night for Teddy.

Source: ABC

The doctors work on a Jane Doe, who turns out to be the subject of a case that gained national interest; Cristina proves to be the highest in demand as the residents begin their interviews for post-residency positions at prospective hospitals; and Richard is faced with an unsettling realization when he visits Adele at Rose Ridge.

Source: ABC

After eight years of practice, the residents head to San Francisco for their oral boards; sparks fly between Catherine and Richard when they bump into each other at the hotel; Bailey intervenes after Owen and Teddy get into a heated argument about their young car crash patient; and Mark tries to recruit Lexie for one of his cases. Meanwhile, Alex feels guilty for being away from the hospital when Tommy's health begins to fail.

Source: ABC

The residents agonize over their oral boards, reliving every answer they gave during their exams; Arizona's close childhood friend comes to Seattle Grace for medical help; the doctors work on a patient who is missing one third of his skull; and Julia asks Mark to start a family with her. Meanwhile Catherine tells Richard that one of his residents has failed.

Source: ABC

The residents determine their future as they make their final decisions regarding post residency positions; Mark admits to Derek that he is torn between his love for Lexie and the fact that Julia can give him everything he's ever wanted; Ben plans something extra special for Bailey, but she is preoccupied with her work; and Arizona encourages her childhood friend, Nick, to have surgery. Meanwhile a couple on their third honeymoon come to the hospital complaining of mysterious symptoms.

Source: ABC

Faced with a life threatening situation, the doctors must fight to stay alive while trying to save the lives of their peers; Bailey and Ben make a decision regarding their relationship; and Teddy is presented with a tempting offer. Meanwhile, Richard plans a special dinner for the residents.

Source: ABC

The doctors of Seattle Grace are faced with the aftermath of last season's plane crash. As they try to move on with their lives, they must learn to adapt to the changes, cope with their losses and move forward with their relationships and careers.

Source: ABC