When Ted's best friend Marshall proposes to his girlfriend, Lily, Ted realizes he'd better get a move on if he hopes to find true love. Ted soon meets Robin in a neighborhood bar, immediately becomes smitten and scores a first date. But when Ted can hardly wait to see her again, his eagerness threatens to scare her away.
In a desperate attempt for a second date, Ted invites Robin to a party he is throwing. However, she doesn't show up and he keeps throwing parties in the hopes she will finally arrive.
Ted agrees to let Barney spice up his love life, and ends up on a crazy adventure of flying to Philadelphia, encountering the law and visiting the Liberty Bell.
Ted's outlook on his continuing search for love is altered when he rediscovers a shirt that has not seen daylight in years. Meanwhile, Barney amuses himself by coaxing Robin into sacrificing her job by saying completely outlandish things on air live for a cash reward.
Ted and Barney start checking out the club scene with their friend Robin, whereas Lily and Marshall try to participate in some more "grown-up" activities, as they draw slowly nearer to their wedding.
Ted makes his yearly pilgrimage to the rooftop Halloween party in search of a girl dressed as a pumpkin who he met years ago. Meanwhile, Robin is dumped after driving her new boyfriend away with her independent ways.
When Ted turns to a matchmaker to find love, he is sent away matchless.
When a matchmaker with a 100 percent success rate turns Ted away because he is not compatible with any of the available women in her database, he is still determined that he is going to find his match. After getting information from the matchmaker’s computer on the sly, Ted pays a visit to a very cute, but very taken, dermatologist in an effort to debunk the prediction that there are no women out there for him. Meanwhile, Marshall and Lily are obsessed with ridding their apartment of an unsightly critter.
As Lily becomes more of a permanent fixture in Ted and Marshall's apartment, Ted feels like he is being edged out of the mix by his engaged roomies. Petrified of being left alone and homeless, Ted tells Marshall that when he and Lily are married, he wants the apartment. The problem is that Marshall wants to keep the place too, so they settle it like real "grown-ups"--launching into a sword fight that leaves one man down for the count.
When Ted and Robin decide to help feed the homeless on Thanksgiving Day, they are in a state of disbelief when they run into Barney and discover that he is a regular volunteer at the homeless shelter. Thanksgiving doesn't end there for the trio, for they end up somewhere that only the "real" Barney would bring anyone to for a holiday meal. Meanwhile, things do not go very smoothly when Marshall and Lily pay a holiday visit to Marshall's family in Minnesota.
After Ted overdoes it during a night out on the town, his friends help him to put together the pieces of his antics the next morning.
With the encouragement of his friends, Ted decides to let his hair down for a change and ends up having a fun and adventure-filled evening. However, now the problem is that he can't quite recall everything that transpired over the course of the evening and now he must rely on his friends to fill him in on the night's misadventures.
Ted surprises his friends with a styling and well-planned out New Year's Eve excursion around the Big Apple.
After spending New Year's Eve apart from his friends last year, Ted is dead-set on ringing in this new year with his best pals at his side and doing it in style. As Lily, Marshall, Barney and Robin are chauffeured around town in a limo hired by Ted, the night takes some interesting twists and turns -- and when the clock strikes twelve, Ted may end up getting that kiss he has been longing for or at least the promise of something good to come.
Ted is planning to bring Robin as his date to a wedding but the bride says he did not RSVP with a guest. When he goes around her and gets permission from the groom, a man named Stuart. Ted's fantasy with Robin is in trouble unless he finds a way to get them back together.
At a wedding, there's instant attraction between Ted and a woman. Both agree to preserve the evening in memory by not exchanging names or numbers, but Ted falls too hard to let it go and tries to find out her identity.
After agreeing to take things slowly and not have sex for a month, Ted and Victoria decide that they have waited long enough. With Marshall and Lily out of town, the timing seems perfect. However, when the two change their plans and decide to stay home, they end up hiding in the bathroom in an effort to avoid ruining the moment for Ted. Meanwhile, Robin replaces Ted as Barney’s wingman for a boy’s night out.
As Barney shares his most embarrassing moment with the gang we see flashbacks of what he was like before he started wearing suits all the time and sleeping around, and learn what caused him to change.
Just as things are going so well with Ted and Victoria's relationship, Victoria gets her dream offer and the couple is confronted with some hard decisions about their future. Meanwhile, when Lily ruins a very expensive wedding dress and Barney talks Marshall into buying a very pricey suit, Marshall is forced to interview at Barney's company and give up his dream of working for an environmental law firm in order to earn more money.
After a rough start on the new job at Barney's company, Marshall conforms in order to be accepted by his crude and obnoxious "frat boy" co-workers. However, he soon realizes that staying true to himself and his relationship with Lily is what is truly important. Meanwhile, Ted is convinced that Victoria is going to dump him after receiving a "let's talk" e-mail, so when the phone rings and it is Robin inviting him over late night, Ted must decide between going to Robin's place or waiting for Victoria's call.
Convinced Victoria is about to dump him, Ted accepts a late night invite to Robin's place. When Robin inquires about his relationship with Victoria, Ted tells her that they broke up. As things start to get hot and heavy between them, Ted's lies are eventually exposed and his theory "nothing good happens after 2 AM" proves to be true. Meanwhile, Barney tries to convince Marshall and Lily that the best things actually do happen after 2 AM
Everyone is invited to a banquet when Robin is nominated for a news award, and Barney sets Ted up with a hot "date".
Lily and Marshall's wedding date has just been pushed up, and in order to hear a potential band for the big wedding, Lily crashes a high school prom.
When Lily's car breaks down on the way to a secret appointment, Ted changes a very important date to come to Lily's rescue. However, Lily drives off after confidentially telling him that she is on her way to an interview for a summer arts program that would derail her wedding. Despite Ted's input, Lily decides that she must go through with the interview or she will always wonder what could have been. After several months, the matchmakers finally comes through with a match for Ted.
In an attempt to capture Robin's heart, Ted declares his love to her. Once again, Robin resists and prepares for a weekend away with her co-anchor, Sandy. Ted makes one last romantic gesture which leaves their fate as a couple in Robin's hands. Meanwhile, when Marshall finds out about Lily interviewing for a summer program, a heated fight ensues.
The gang tries to help Marshall get over Lily. Barney takes him to a strip club, and Ted takes him to a Yankee's game. Marshall finds a credit card trail that leads to Lily's hotel in the city, but the guys try to keep him from going to see her.
Barney teaches Marshall how to pick up women. When things start to go sour for an awkward Marshall, Barney steps in and wins the women over... for himself. Meanwhile, Lily is back from her art experience. While helping her look for a new apartment, Robin gets sick of hearing about Lily's amazing summer in San Francisco.
When Ted's parents come to New York for a visit, their weekend ends up being far from the ordinary when a colossal family secret is unveiled.When Ted, Robin and the gang spend the weekend with his parents, Ted is stunned when a family secret that changes things forever is unveiled at brunch. Meanwhile, Marshall and Lily find it difficult to control themselves when they are forced to spend time together with Ted's parents.
When Barney tries to prove to Ted that his job as an architect is anything but boring by showing him that it is a great way to pick up women, a jealous Robin tracks down her man after hearing of his antics.
After a fight in which Robin insinuates that Ted's job is boring, Barney sets out to convince his buddy otherwise. As the guys test out the pick-up line, "Ted Mosby, Architect" on the ladies, they realize it really works. But when Robin hears that Ted is parading around town picking up girls, she is hot on his heels to discover the truth.
Lily moves into Barney's apartment and the trials, troubles, and tribulations may be a bit too much for poor Barney to handle.
Barney takes it on himself to please Marshall's disgruntled law professor, while Lily gets a job at Ted's architect company and tries to teach Ted's boss a big lesson.
Marshall starts dating a woman and they really hit it off, but Barney and Ted tell him he has to dump her because she has "crazy eyes."
Marshall and Lily, together again, decide to elope in Atlantic City, and they gather Barney, Ted and Robin to take part in the wedding.
Barney uncovers Robin's secret past and the real reason behind her strong aversion to malls.
Barney's black, gay brother, James, visits and Robin, the only one in the group who's never met him, is surprised. But James has a surprise for Barney that he finds hard to accept.
Ted almost ruins Christmas for everyone when, still carrying around anger toward Lily, he calls her a horribly disgusting name.
Robin wants to tell Ted she loves him, but she can't make the leap. Meanwhile, her sister visits and brings her boyfriend, and Robin doesn't react well when her sister says she's ready to lose her virginity.
When Ted is constantly insulted by his former boss, who is now working for him on a project, he is told to fire the man, but he finds that a hard thing to do. Meanwhile, Barney offers Lily a lot of money to paint a nude portrait of him.
Marshall visits Lily's kindergarten class for show and tell, and a little boy blackmails Doug with the score of the football game. Robins on the air.
Ted finds a "lucky" penny, and even though bad luck starts to follow him, it may be the best thing to ever happen to him.
After Robin gives Ted grief over keeping all of his gifts from ex-girlfriends, Ted decides it's time to give them all away. However, the tides change when he finds that Robin has been holding on to items as well.
Marshall's beloved 1988 Fiero dies just short of reaching the 200,000 miles mark, leading the gang to relive their greatest memories in the car.
As Ted and Robin hit a new milestone in their relationship, Barney does everything he can to derail their happiness. To do so, Barney steals the rental truck Ted is using for moving day, including all the belongings inside of it.
When Barney ruins Marshall's bachelor party plans, Lily reveals information about Barney that forces Marshall to rethink his best man choice.
Barney is chosen as a contestant on "The Price is Right," giving him the opportunity to fulfill one of his life wishes: to meet Bob Barker.
Lily and Marshall's wedding day arrives, but nothing goes as they had planned. Surprisingly, Barney steps in to save their once-in-a-lifetime moment.
Barney overhears that Ted and Robin have a secret, leading him to wonder what it might be. When the secret is revealed, the truth stuns even Barney.
Robin begins to date a hunky Argentinean, leading Ted to go out with Barney for a legen...wait for it...dary night to forget about Robin moving on.
After seeing girls swoon for Robin's boyfriend, Gael, because he's not from New York, Barney and Ted try to pull themselves off as out-of-towners in order to meet girls.
Two women become very interested in Ted and end up taking the party to his place. The gang must show Ted that bad luck doesn't come in threes.
Robin dates a single dad, and to her surprise, bonds with the man's son, which causes her to worry that the relationship is too serious.
Ted's new girlfriend becomes jealous that the story about how Ted and his friends met is better than how she met Ted, resulting in her ranking on Barney's "crazy scale" to go through the roof.
When a law firm tries to recruit Marshall, Jeff Coatsworth is able to win him over, forcing Marshall to stray from his dream to save the earth.
Lily and Marshall decide to buy an apartment, but nothing goes as it should. Later, Marshall learns about Lily's financial secrets when they apply for a loan.
Ted thinks he may have met the perfect girl, but the gang points out a flaw that changes his opinion of her, leading to a heated argument.
Lily and Marshall have their first Thanksgiving as a married couple; Barney is tortured by the slap bet countdown clock, worrying about when the slap will be dished out.
Barney loses his 'mojo' and heads to the Victoria's Secret Fall Fashion Show party to try to get it back, but he's put to the test when he meets Heidi Klum.
Ted's friends try to discourage him from going on a date with his doctor, a person he sees regularly, by telling their own bad experiences.
Ted decides to take on Barney's lifestyle for St. Patrick's Day, which would likely include activities which are very un-saintly.
After Ted is repeatedly rejected by his dermatologist Stella for a date, Abby, her receptionist becomes interested in him.
Barney's love life falls victim to a mystery woman, forcing him to use a tournament bracket to narrow down a group of 64 women who have a reason to hate him.
When Marshall is verbally emasculated by his boss, he begins to think that taking a job with a corporate law firm was a big mistake.
Robin rekindles a spark with an old flame, but he ends up breaking her heart again. Barney and his own inimitable style helps make her feel better.
As Ted prepares for his thirtieth birthday by getting rid of old stuff he’ll no longer need, Barney and Robin struggle with the ramifications of their night together and whether or not to tell Ted. Barney enlists Marshall’s legal expertise to find a loophole in "The Bro Code”, a list of do’s and don’ts for all bros, but ultimately decides he just needs to come clean. And in a surprise blow, Ted "breaks up” with Barney, realizing their lives are going in a different direction and he’s tired of the single life.
Ted may have ruined his relationship with Stella after he reveals an intimate secret about her to his friends.
As a couple, Abby and Barney have decided they agree on one thing, they both hate Ted, and decide the bar is a great place to flaunt their romance in front of him. Barney goes a bit overboard by doing something impulsive.
Ted re-evaluates his life and his relationship with Stella after a close call with death from an accident.
As Stella finally gives Ted an answer on his proposal, Barney realizes that he may be in love with Robin.
Barney, Lily, Regis Philbin, Robin, Marshall and Ted set out on a mission to find the restaurant in which Marshall ate his first New York burger.
Ted tries convincing his friends that city living is much better than living in the suburbs by inviting them to Stella's apartment in New Jersey. Stella shocks him by announcing that she wants to live there permanently once they marry.
Ted insists that his friends attend an intervention after learning that they had previously ditched it for his engagement to Stella.
Ted and Stella makes the decision to get married in three days. But then when the day comes it's not all what they had imagined because of the presence of their exes.
When Ted unexpectedly runs into someone from his past, that he would rather have stayed forgotten, the gang starts wondering how they would handle it, if it happened to them.
Lily and Marshall receive different views on whether they should have a baby when Lily asks Ted and Marshall turns to Robin for advice.
Robin meets back up with a group of over-indulging single party girls known as the "Woo Girls." Meanwhile, Barney receives a submission for design of the new company headquarters from Ted.
Ted walks into his apartment to Robin's date sitting naked on his couch. He learns about a technique that could revolutionize dating for the whole group, and everyone thinks about whether or not they should try it out that night.
Ted tries to prove to the gang that he's not a loser after being left at the alter. Meanwhile, Barney and Ted decide to pick a fight with the guys sitting in their favorite booth to impress Robin.
Ted's younger sister comes for a visit; meanwhile, Marshall introduces Robin to her first theme bar.
When Ted and Robin decide to be "friends with benefits" to end conflicts around the apartment, Barney tries to fix their problems so they will stop sleeping with each other.
Lily comes back from a trip to Seattle only to run into a blizzard, which may threaten an airport ritual of meeting Marshall. Meanwhile, Ted & Barney offer to keep watch over the bar at MacLaren's while awaiting their dates, since Carl wants to close up early.
Robin discovers she must find employment within four days or be deported back to Canada, and agrees to create a video resume with Barney's help.
The gang feels Barney has a girlfriend after he inexcusably leaves MacLaren's.
When Lily and Marshall get wind of the fact that Ted's college girlfriend has moved to New York, they decide to reveal to him how much they hated her.
When Karen comes across another woman's earring in Ted's bed, he learns that Lily put it there on purpose leading Ted to discover this isn't the first time she's covertly meddled in his relationships.
As a means of protecting Ted from discovering he has lost an important job, Marshall and Barney dream up an intricate lie.
When Barney learns Ted has a list of things he thinks the gang is too old to do, he sets out to do every task within 24 hours in order to prove Ted wrong.
Ted decides to use his apartment as his new architecture firm and hires an intern, but he becomes a bit too friendly with Ted's buddies.
Ted breaks one of Barney and Marshall's relationship rules, texting a woman he recently met, so the pair play a joke on Ted by pretending to be the woman.
Ted explains to his future children how important it is to be in the right place at the right time. Meanwhile, Barney celebrates his 200th conquest.
Tony, Stella's fiancé, makes an attempt to ease the burden he feels for "ruining Ted's life," by helping him find a job, but instead proves that no good deed goes unpunished. Meanwhile, Barney wants to prove that he can get out of a speeding ticket.
Trying to keep his architecture firm afloat by doing an all-nighter, but Marshall tries to lure him to the roof for a surprise 31st birthday party, on the fourth season finale.
When the gang finds out that Barney and Robin are hesitant to define their relationship, Lily forces them to confront their biggest fear...becoming boyfriend/girlfriend. Meanwhile, Ted is anxious about teaching his first lecture at Columbia
Barney takes Marshall, and Robin to a strip club where they find a stripper who looks almost exactly like Lily. Meanwhile, Ted discovers he had been fixed up with the same woman, Jen seven years earlier.
When Robin fears that Barney is cheating on her, she soon discovers that he is spending his evenings with Ted learning everything there is to know on how to date her.
Marshall and Lily want to hook up with Barney and Robin for double-dating and fun, but their desperate eagerness to please is a huge turn-off. Meanwhile, when a succession of girls come to his apartment and immediately fall asleep, Ted is bummed to learn he is a "Sexless Innkeeper" whose "dates" are only interested in a comfy place to crash
Barney tries his best hoping to convince Robin into becoming an American citizen, while Ted and Marshall's road trip takes an unexpected turn for the worst when Marshall invites Lily to come along.
Even though they do their best in order to be the perfect couple, Barney's attitude of know-it-all lands him in trouble with Robin and they are forced to seek Marshall and Lily for advice.
Lily comes up with a perfect plan to break up the relationship between Barney and Robin when they have a rough patch, but she needs help from Robin's famous friend, Alan Thicke, in order to make it work.
After his relationship with Robin ends, Barney uses all his skills and greatest tricks to get himself back into the dating scene.
When Lily's estranged father shows up unannounced on Thanksgiving, we learn what led her to stop speaking to him three years ago
When a perfect girl finally shows up, the gang tries everything to help Ted, while Marshall takes action when he discovers a letter written by younger himself.
While Robin clashes with her new jaded co-worker, the gang tries their best to quit smoking.
On the 100th episode, Barney must choose if he should give up wearing suits in order to land a hot bartender, but his conflicted feelings result in an amazingly awesome musical number. Meanwhile, Ted gets closer to meeting the future mother of his kids.
After Marshall's attractive female colleague kisses him, Lily refuses to believe it, resulting in Marshall convincing Jenkins into telling Lily that it really happened. Meanwhile, Robin uncovers a drinking game which, apparently, is made up about her.
When Barney is about to complete the perfect week - landing seven different girls in seven days - the gang roots him on in order to forget about their own miserable week.
After forgetting to get Ted a blind date on Valentine's Day, Lily and Marshall go after the many discarded girls Barney has dated in order to see if any of them can be Ted's future wife. Meanwhile, Robin is invited to a party by an obnoxious colleague.
When the gang tries to convince Ted that he is being strung along by Tiffany, they reflect about relationships where each of them has been in the same situation.
When Robin confesses that she is still angry with Barney for the way he handled their break-up, she enlists the help of Anita, a self-help author who plans to beat Barney at his own game.
When Ted ruins Lily's birthday dinner celebration by bringing a date, Lily goes to great lengths to keep her out of the traditional photo she takes every year of the gang.
When Marshall gets mugged, Lily decides she wants to get a gun for protection, so Marshall comes up with a convoluted story about the mugging to deter Lily from following through
When Ted attends his mother's wedding, he is extremely disturbed by her overly affectionate relationship with her fiance, which forces him to think about his own life and make an impulsive decision
When Ted and Barney jeopardize Robin's new relationship by professing their love for her, Robin realizes that she is finally over them. Meanwhile, after spending a weekend sleeping in twin beds, Marshall and Lily decide to get twin beds at home
Crashing a snobby high-society party allows Ted to show off how pretentiously intellectual he can be.
When Ted takes a date to see a new hit movie, "The Wedding Bride," he is shocked to learn the story is loosely based on his life, and that it was written by Tony, the man Stella left him for at the altar.
Marshall and Lily make a secret pact to start trying to have a baby if they ever finally see Barney's doppelganger. Meanwhile, Robin finally gets an offer for her dream job.
When Ted and Barney argue about who has "dibs" on a hot girl, Ted realizes that she is there with Cindy, a girl he previously dated who is also the roommate of his future wife. Meanwhile, Robin is heartbroken over Don, and Marshall can't keep quiet about his desire to start a family
While helping Barney's mother move the gang realize quite quickly that Mrs. Stinson has always been very protective of Barney and because of that lied to him quite a lot. Meanwhile, Robin sets Ted up on blind date.
When Ted declines Barney's offer to design the new GNB building, Barney ties to woo him by using all of his best womanizing tactics. Meanwhile, Robin is still not over her relationship with Don and drunk dials him.
When the gang is making fun of Robin because they don't think she is a real New Yorker, she challenges them to a race, first one to get to a downtown restaurant and catches a glimpse of Woody Allen wins.
When Ted meets a hot girl who opposes the new GNB building being built he starts wondering if he really should take the job.
Marshall and Lily research how to conceive a baby with the gender of their choice. Meanwhile, Robin is growing more and more irritated by her perky new co-anchor, Becky.
When Zoey enrolls in Ted's class, she manipulates his students into taking her side in the fight to save the building being torn down to make room for his project. Meanwhile, Marshall and Lily spot Robin marching in the Halloween parade of shame.
When the gang attends a black tie fundraiser at the Natural History Museum, Ted runs into Zoey and sees a whole different side of her when she introduces him to her husband, The Captain.
When Barney finds a copy of the Canadian kids show "Space Teens" starring Robin's alter-ego "Robin Sparkles," the gang learns more about Robin's past as a performer than they expected.
When Ted leaves the bar early to prepare a Thanksgiving feast for his friends, the gang winds up partying all night with The Blitz, an old friend from college who has bad luck.
When Ted's new friendship with Zoey tests the theory that men and married women can't be friends, he invites her husband, "The Captain," to hang out with them. Meanwhile, Marshall and Robin decide to spend alone time together.
When Marshall and Lily receive shocking news, it has a profound effect on the gang and forces them to reexamine their own lives.
Meanwhile, Robin gets a new job, Barney discovers the joy of giving on Christmas and Ted begins his duties as Best Man for his old friend Punchy's wedding.
When Marshall and Lily fear they will never get pregnant, they see a specialist who can hopefully help move the process along. Meanwhile, Robin starts her new job.
The gang travels home to Minnesota with Marshall where Ted and Barney will stop at nothing to make Marshall laugh. Meanwhile, Marshall has an unfortunate meeting with an old high school bully that terrorized him throughout his youth.
When Zoey fixes Ted up on a date with her cousin, the gang resorts to calling her "Honey" after learning how naive she is. Meanwhile, Ted calls an intervention on himself after having an epiphany about his feelings for Zoey, and Barney gets acquainted with Honey in Ted's place.
Barney declares February 13th "Desperation Day," a holiday for desperate women. Meanwhile, Lily surprises Marshall for Valentine's Day, Ted and Zoey continue to figure out their relationship and Robin bonds with her single girlfriends.
After Marshall sees a documentary about garbage, he becomes fixated on saving the environment. Meanwhile, Ted runs into Zoey's ex-husband, The Captain, and Robin forces Barney to admit he has feelings for Nora, the girl who made history as his first Valentine's Day date ever.
When Barney starts to have real feelings for Nora, he worries that there is something wrong with his heart. Meanwhile, Robyn starts dating a guy who acts a lot like a dog.
When Barney finally meets his father, he's surprised to learn how his life turned out. Meanwhile, the gang points out each other's "gaps," something they should know by adulthood but never learned.
Lily and Barney react badly when Marshall finally quits his job at Goliath National Bank to take a volunteer position at an environmental organization.
Meanwhile, Ted and Zoey's opposing positions on the future of The Arcadian come between them.
When Barney tries to bond with his father, he asks the gang to help make his life seem more exciting by lying about their own lives. Meanwhile, Robin runs into a guy she has a crush on.
When Marshall and Barney argue over the destruction of the Arcadian Hotel, Robin and Lily try to mix the right combination of cocktails that will force them to make up. Meanwhile, Ted plans a romantic weekend away with Zoey.
When Ted is faced with an important decision that might affect his future with Zoey, the gang expresses their true feelings about her.
Robin and Barney bond when they intervene in Ted's relationship (until they run into Nora), and Marshall and Lily watch a ticking clock as he fears that he soon will be the victim of food poisoning. Meanwhile, Ted performs his Best Man duties at a very important wedding.
While Barney prepares for his wedding to a mystery bride, he and Ted reminisce about Punchy's wedding, including when Marshall and Lily announced they are having a baby. Meanwhile, Robin considers telling Barney she has feelings for him.
When Marshall gets the job of his dreams, he worries that, once the company discovers videos he made in the past, they may rescind the offer. Meanwhile, Ted can't decide who to bring to the Architects Ball.
After Ted runs into an old girlfriend, he tries to make amends with her since he cheated during their relationship. Meanwhile, Marshall and Lily make a bet with Barney that could force him to wear Marshall's ducky tie.
After Robin assaults a girl who is out to ruin Barney's relationship, she is forced to begin court-mandated therapy sessions. Meanwhile, Ted gets too involved in Lily's pregnancy.
When Marshall witnesses his boss's soft approach in settling with a million dollar company, he takes matters into his own hands. Meanwhile, Ted takes his architecture class on a field trip and things don't go as planned.
When Ted goes on a date without researching the girl on the Internet, the gang interferes, showing Kevin that they are too into each other's business. Meanwhile, Lily and Marshall come to terms with finding out the sex of their baby.
The gang begins to realize their romantic partner reminds them of one of their parents. Meanwhile, Barney and Nora's planned romantic evening is ruined by a string of bad events.
Ted finally meets his mystery girl in the Slutty Pumpkin costume. Meanwhile, Barney learns he is part Canadian, and Lily has pregnancy brain.
While the gang reminisces about Hurricane Irene, Barney tries to cut a deal with Marshall and Lily to get out of wearing the Ducky Tie.
Barney and Robin find themselves in an uncomfortable situation when they hide a secret from their significant others. Meanwhile, Marshall, Lily and Ted attend a concert.
Ted and Barney discuss making a life-changing decision together, and Robin tries to discourage Marshall and Lily from moving to Long Island.
When Robin receives bad news, she decides to lie about it to the gang. Meanwhile, Marshall hangs Christmas decorations on the house in the 'burbs with help from his neighbor.
After celebrating New Year's Eve, Marshall visits his father's graveside to carry on their tradition of tailgating. Meanwhile, Barney and Ted open a bar called "Puzzles," and Robin is forced to fill in for an inebriated news anchor.
Lily and Marshall officially move to the suburbs and realize that Lily's bossy father refuses to move out of their house. Meanwhile, the gang adjusts to them moving by going to a strip club.
Lily and Marshall throw a housewarming party, where Ted nearly comes to blows with Marshall's boss, and Barney hits on a crazy divorcee.
For Valentine's Day, Lily and Marshall invite Robin and Kevin on a weekend getaway to Vermont, where Kevin and Robin discussing taking their relationship to the next level. Meanwhile, Barney realizes he has finally met his match.
When Robin breaks up with Kevin, Ted confesses his feelings to her. Meanwhile, Barney is on a mission to find something private of Marshall and Lily's.
Now that Robin has moved out Ted tries to figure out what to do with her old room. Meanwhile Robin joins Marshall and Lily in the suburbs.
The gang tries to break up Barney and Quinn after learning they plan on moving in together, leaving Robin and Ted to fight over who deserves to sublet her apartment.
Ted, Marshall and Barney embark on another "trilogy time," where they get together every three years to watch the "Star Wars" trilogy and envision what their lives will be like in another three years. Meanwhile Barney and Quinn move in together.
Just as Ted starts to settle into his new apartment alone, Barney tries to entice him into going out every single night. Meanwhile, Lily has a naughty dream about someone other then Marshall, and Robin finally becomes a famous news anchor.
When Lily and Marshall have a baby shower, Marshall starts to panic after realizing the baby is coming soon. Meanwhile, Ted and Robin come to terms with their relationship and Barney takes Marshall on a road trip.
While Marshall is in Atlantic City with Barney, Lily goes into labor, leaving him desperate to make it back to New York before the baby is born. Meanwhile, Ted and Robin try to distract Lily during her painful contractions.
On Barney's future wedding day, when his wife is finally revealed, the gang reminisces about the time they encouraged Ted to follow his heart and go after the one that got away.