The episode begins with Meredith trying to potty train Zola. Meredith leaves for work and Zola cries. Back in Minnesota, Cristina gets a ride from Dr. Thomas, who picks her up in his old sedan. At the hospital, they meet the patient and tell her about it and the process they're going to use. It turns out the patient and her boyfriend, are "Doomsday Preppers," ready for the apocalypse. Dr. Thomas and Cristina try to compose themselves. Meredith chats with Cristina on her way into work and she sees a car accident. Meredith stops to see if anyone needs help. She finds a young woman named Melissa trapped under a car after being hit by it while riding her bike.
Meredith shouts for any of the many bystanders will help her pull the car off Melissa, who can't breathe. None of them wants to be responsible if it goes wrong. Finally, several people decide to lift one side of the car and Meredith pulls Melissa out from under it. Melissa breathes. Back in Minnesota, Dr. Parker asks Cristina to scrub in with her on a gastro pericardial fistula and she says she can't because she's doing the aneurysm with Dr. Thomas. Meredith shows up and delivers instructions on what to do with the patient. She tosses her keys to an intern and tells her to go get her car from where she left it. She also tells the intern to get the fish sticks from the back of the car, "nuke 'em" and take them up to day care for "Brazil Day." It was Bailey's intern. Cristina is going over scans with Dr. Thomas when Dr. Parker sees them. He pulls Cristina aside and tells her the aneurysm is "a disaster area".
He tries to take her off the case, saying there's nothing to gain by working with Thomas, but she thinks there is, and she leaves. Meredith is operating on Melissa. Callie shows up to assess bone damage. Callie forgot it was Brazil Day at day care. Cristina and Dr. Thomas are operating on the aneurysm and Parker shows up to see it all. Thomas is surprised by the second visit in the same day and tells Parker he knows that he just wants to observe his "inevitable demise". An artery is hit and there's a lot of blood splattering around when Parker decides to scrub in. Thomas says he has it under control and he and Cristina put clamps in place to stop the bleeding. Meredith is trying to save Melissa's liver when Webber instructs her to stop because she's doing more damage than good.
He says they need to pack her up. Webber says Melissa's body has sustained a lot of damage after getting hit by so much crushed steel, and Meredith snaps back that she knows exactly what that feels like. She wants to keep going, but Webber insists and Meredith stops. Back in Minnesota, Parker yells at Thomas about the "train wreck" of his surgery. Thomas saved the woman's life, but Parker claims he's a danger to the hospital's patients. He asks Thomas to hand over his license, but Thomas says he won't step down. Parker says he wants to sign off on everything Thomas does from now on. Thomas leaves. Parker asks Cristina to talk to him. Webber asks Meredith if she wants him to take over Melissa's case because she's the same age and has the same injuries as Lexie did.
He thinks emotions are clouding Meredith's judgment. She says they're not, and she leaves. Cristina and Meredith both leave their patients for the night to see how things will go in the morning. Meredith runs into Jackson on the way out of the hospital, who is on his way back in because one of his interns made a potentially lethal mistake with his patient. Meredith decides to stay at the hospital overnight and leaves Zola with Callie because Derek is away. She feels guilty leaving, but Callie encourages her, saying it's good for Zola to see her working. Meredith and Cristina talk to each about their patients while sitting outside of their rooms. They each check their patents' vitals while chatting on the phone.
They want to have a 30-second dance party, but are both too tired. The next morning, Thomas wakes Cristina up and the interns wake Meredith up. Both of their patients need another surgery. Callie shows up with Zola and hands her to Meredith. Zola has a slight fever and day care won't take her. Callie has a surgery in 10 minutes. Meredith hands Zola to the same intern from earlier and tells her to monitor the fever. In Minnesota, Cristina is worried Dr. Parker won't sign off on the next surgery Dr. Thomas wants to do. Dr. Thomas, in response, tells Cristina he "objects" to her "extracurricular gymnastics" with Dr. Parker. Cristina is stunned that he knows. Thomas says her affair with Parker is making her skittish and conventional.
Meredith tries to treat Melissa while Zola is crying. Bailey tells Meredith that the crying is pulling Meredith's focus because women are genetically predisposed to respond to crying. The boyfriend of Cristina's patient is getting nervous about the risk involved in her next surgery, but she says it'll be fine. She asks Cristina to tell him it will be fine. In Seattle, Alex steps up to take care of Zola. Meredith and Cristina chat again about how each of them needs to "step up". Cristina needs to confront Dr. Parker about threatening Dr. Thomas' job, and Meredith needs to open up her patient again to try to save her life.
Cristina goes to Dr. Parker and asks him to take Dr. Thomas off probation. She says Dr. Thomas did a great job on his patient's aneurysm. She asks Dr. Parker to "let this slide". Dr. Parker tells Cristina that Dr. Thomas is holding her back, "and once he's gone, you'll see that". Cristina finds Dr. Thomas sitting outside in the cold. She tries to talk him into letting her do the surgery with someone else so he won't lose his job. He says that if he's going, he wants to go down fighting. Meredith tells Webber she has a window to perform another surgery on Melissa. Webber says nothing. Meredith defends herself, saying she's going to try to do everything she can, and she insists, "it’s not Lexie".
Webber tells her, "Good luck and it's the right call". On the way to the O.R., Meredith runs into April, who is supposed to be watching Zola. It turns out, April's surgery went long and Zola ended up with a nurse named Ted, who Meredith doesn't know. Meredith sends one of her interns to make sure he doesn't leave April's side until Zola is physically in her arms. Meredith and Cristina do their surgeries, which we see in a split screen for a while. Dr. Thomas tells Cristina that if their surgery goes well he's going to put her name first when they write about it in a journal. During the surgery, he has a heart-to-heart with Cristina about how she needs to appreciate the women who came before her to help pave the way in medicine.
Then he says he is going to put his name first in the journal article because Cristina is going to be the surgeon of her generation and he wants it known in the medical community that he had a part in training her. Meredith figures out where her patient's bleed is coming from, then forces her interns to participate in a 30-second dance party. Cristina asks Dr. Thomas for a suture and he doesn't respond. He looks up at her for a moment, then falls backward onto the floor. As her patient starts to bleed, Cristina keeps working on her and tells the nurses to take care of Dr. Thomas. Cristina keeps working on her patient while calling out instructions for trying to resuscitate Dr. Thomas.
Dr. Parker comes in and tries to piece together what's going on. He didn't even know the surgery was happening. He tells Cristina to focus on her patient while he tries to get Dr. Thomas breathing. Cristina reminds herself to breathe a tip Dr. Thomas had just given her. Cristina goes out to report to Katie's husband that she has a strong heart and did well. He hugs Cristina, who turns around and sadly walks back toward the O.R. She sees Dr. Thomas carted away with a sheet over him. Dr. Parker extends a handshake and Cristina walks right by him.
We see Cristina sitting alone and getting ready to leave for the night while Dr. Thomas' wise and encouraging words echo around her. Meredith looks for Zola and finds Hunt holding her. He took over for April a while ago. Meredith's intern comes to get Meredith, who says Melissa is asking for her. Meredith goes to see Melissa, who remembers that she was "trapped under something" and Meredith was there. Outside the room, Bailey hands Meredith her list of "Trucker-approved babysitters." She tells Meredith she needs a deeper bench.
That night, Meredith puts Zola to bed and the doorbell rings. It's Cristina. She's completely wasted. Meredith says out loud, "Lexie's dead". They hug and Cristina says, "Everyone's dead". The episode ends at this point.