The residents are all on edge with it being their fifth year, and all are trying to score surgeries that will look impressive for their boards and which will only have positive outcomes. Alex works with Teddy in cardio, Cristina with Callie in ortho, April assists Bailey with the mice for the clinical trial, Lexie assists Derek, and Jackson... is largely not in this episode. Since Mere is off neuro and no one really wants to work with her, she winds up in OB wearing pink scrubs and delivering babies. In doing so she gets a patient who conveniently has an inoperable brain tumor. She realizes that because of the nature of this particular "inoperable" tumor the Brilliant Dr. Shepherd might be able to remove it after all, and she also wants to see Derek happy since he's really bored with nothing but routine cases. However, she's trying very to play by the rules and not talk neuro with Derek so she enlists Lexie to tell him about the patient in case he really might be able to remove the tumor. Unfortunately Lexie does a horrible job selling it, so Mere has to orchestrate her every little move from behind the metaphorical curtain to get Derek to take an interest in the case. Oh yes, I forgot to mention: one of the reasons Mere really wants to play by the rules now is because she and Derek are kind of inexplicably back to being all kissy and cute, to the point where I feel like we somehow missed an episode in which their relationship turned around. Regardless, with her behind-the-scenes scheming Derek winds up operating on the woman, saving her life, and is so excited he wants to tell Meredith about it but she actually tells him not to and distracts him with nookie.

Cristina is also distracting someone with nookie -- actually, three someones. The first two distractees are she and Owen, because they still can't really find anything to talk about since they haven't addressed the abortion, but they've managed to start filling in all of the awkward silences with sex all over the hospital. Richard keeps managing to accidentally stumble upon them in the act, and he yells at Owen to pull himself together and act like the Chief now; that means no more sex in conference rooms. He tells Cristina, but when they then encounter another awkward silence they just go home to drown it out with yet more sex. When she's not indisposed with Owen, Cristina and Callie are working on a tricky case that involves rebuilding a guy's spine. They run into some problems and Cristina keeps insisting that they do a less risky procedure instead even though that won't leave the guy with full mobility. When something goes wrong she freaks out and pulls her name off of the case so that she doesn't get a bad outcome on her record, but when it turns out that it was just a loose wire and the patient was fine, Callie refuses to let her back on and later lectures her that she has to start taking risks again if she wants to be great. Alex also gets the same lecture from Teddy when his patient insists on experimental surgery so that he won't have a big scar -- Alex researches it and ultimately decides not to do it because he feels it's too risky (he has a number of negative surgical outcomes on his own record already so he's trying to avoid more) and so Teddy goes ahead and does it anyway without him.

Callie is on edge in general because Mark and Arizona have managed to become BFFs, and the way they bonded was through cooking. She admits she wanted them to get along but now that they are together all the time acting like little Martha Stewarts and it's killing her own sex life with Arizona. Finally one evening she kicks out Mark and orders him to start having some sex of his own again so that he can focus his energies elsewhere and give her and Arizona some much-needed alone time again.

Bailey picks April to help her out on the islet cell clinical trial, and they are both stumped as to why some of the mice are once again diabetic. April has been failing miserably at delegating because no one will listen to her; when she tries to get Alex to do something he winds up yelling at her that part of her problem is that her voice gets all squeaky and ridiculous and no one will ever listen to her like that. She tries out a new, deeper, authoritative voice (and threats) on Meredith and miraculously, it works and she has Meredith do some research on the mice. Richard has been dying to know how the trial is going but Bailey refuses to tell him, so he and Meredith wind up working in secret, doing research to figure out what the problem is and how to fix it. Bailey then catches Mere assisting and blows her lid; April takes full responsibility for delegating the task to Mere but that only gets her fired from the trial too. Meredith finally yells back at Bailey to just take a look at the research and against her will, Bailey realizes that it's good and that Meredith (and Richard, though she doesn't know that yet) might have solved the problem.