Dr. Miranda Bailey (Grey's Anatomy's Chandra Wilson) brings a kidney transplant patient to Los Angeles, in the hopes of getting a last ditch miracle after Izzie blew it at Seattle Grace.
It seems Sam is taking quite a liking to her as well. Interesting chemistry here.
Meanwhile, the consequences of Addison's emotional affair with Noah catch up with her. His wife, with baby in tow, confronts her at the beginning of the episode.
Addison says that nothing happened, which may be technically true as far as the sex goes, but she knows better. Bailey knows too. And doesn't care, of course.
Sheldon and Pete still don't know who the father of Violet's baby is. Will they ever? Yes. Yes, they will. Because Sheldon learns Violet gave Lucas to Pete.
Gave, as in to live, not to babysit. Sheldon is pissed (as pissed as Sheldon gets anyway) and asks her to agree to a paternity test. Violet acquiesces.
Cooper is working on a patient who lives in a bubble. Literally. He is a real-life bubble boy. The guy just wants to go to the high school dance and kiss a girl, but he is too weak. Cooper is working hard to get him to the point where he can go.
Pete is a bit more reluctant to let his fragile immune system handle the outside world and sides with the boy's mother. Pete's parental instincts are kicking in.
It turns out that for Bailey's patient, the last hope she has of surviving is to get a kidney from her sister, who's HIV positive. This is illegal and dangerous.
The recipient's immune system is already compromised and will become more so by adding a strange organ to it, as it will require drugs that battle her own immune system so the new kidney is not destroyed.
In turn, she could develop full blown AIDS, not just HIV, and be worse off than when she started. Sam reiterates that this is also an illegal surgery. He won't be involved. Bailey accuses Sam of being a watcher and not a doer.
The patient wants it, though, so Bailey goes over everyone's head to Charlotte, who likes Bailey's manipulative attitude. She agrees to put a team together.
When it comes down to it, though, the gang is about to start the surgery when one of the key players walks out because he says he cannot be involved.
Sam, who was a cardio-thoracic resident back in the day, says he can step in. He wasn't always a guy who sat and watched, he tells Bailey. Wouldn't you know it, Sam has to save the day in the OR. Woo, Sam!
Afterward, they nearly kiss, but Bailey turns away. We really hope this is not the last we see of these two on the same screen.
Cooper's patient ends up going to his dance, but he's burning up. As in he's got a fever, and not the time that cowbell will cure. Cooper and Pete come to escort him out, but he runs back and kisses his date, just like he always dreamed of.
He promptly collapses to the ground. Best day ever, he says nonetheless.
Coop, who had been struggling with his relationship status, decides he's going to be Charlotte's boyfriend, whether she likes it or not. He literally sweeps her off her feet and takes his woman home to live with him. Cute scene.
Noah's wife confronts Addison yet again. She's figured it out. They didn't have sex, but she ruined their marriage anyway because she knows Noah thinks about her. Loves her. Wants to know her. It's very sad and awkward.
The paternity test is in. It's Pete's. He is ecstatic. Sheldon is devastated.