Callie and Arizona still have a storyline that focuses on their moving in together -- this week it's that they want Owen and Cristina to move out and don't feel like they are taking steps towards this fast enough. Meredith is the one who has to point out to Callie that Cristina can't even sleep if Owen is gone (she goes to Meredith's and crawls into bed with her... and Derek... so that she can finally get some sleep) so Callie then thinks they are monsters for wishing the couple out. It turns out, however, that all she and Arizona needed to do all along was come home and start ripping each other's clothes off right in front of Owen and Cristina before moving into the bedroom for drunken sex, and that gets the newlyweds thinking about their own place right quick.
Cristina is still doing terribly -- during a meeting the attendings all argue about what might be best for her, and most of them think she needs to be moved to administration or something similar for a while. Derek, though, stands up for her on account of her saving his life and puts her on his service, figuring administration is the last thing that would be good for her. It doesn't do a ton of good, though, because Cristina is flippant and sullen and can't bring herself to even answer questions about how they might treat a patient, much less actually help with anything in surgery. Derek finally talks to her and tells her that she's got the most potential of almost anyone he's ever seen, but she finally admits that she doesn't even remember his surgery, except for bits that sneak up on her like in the OR last week, and that she just wants to be left alone. He decides to take a step back, and instead helps her through reenacting his surgery on a corpse, but it obviously doesn't do what Derek wishes it would, as she admits to Owen later that she might be happy being a plumber instead.
Derek has quite a day overall -- in addition to the difficult task of trying to help Cristina, his little sister Amy shows up at the hospital because he's been ignoring her calls ever since he was shot. She brings him a "gift" in the form of a guy with a brain tumor, and he figures out that she met the guy while having a mile-high tryst on the way to Seattle. Amy is also a neurosurgeon, but she seems like a loose cannon and Derek wants nothing to do with her, so he tries to keep her out of the OR and away from him, though fairly unsuccessfully. Mere doesn't get why he seems to hate her until he explains that Amy totaled his car while high on drugs that she obtained by stealing his prescription pad. It turns out that she's always acted out due to her own trauma of being there with Derek when their father was shot and killed, and that all she's really ever wanted to do is actually talk about it with him. When he finally opens up about it, they have a Moment and seem to get back on the right track with each other.
Lexie, Bailey and Mark get a patient whose entire body is covered in warts -- to the extent that his hands look like grotesque gray-green claws and his face looks like he's wearing a fright mask. Lexie flips out when she first sees him and so Bailey makes her work closely on him all day as penance. Lexie feels a little bit better, though, when a spider crawls out of one of the growths during surgery and Bailey starts dancing around and screaming like a little girl, proving that everyone has something about which they can't always stay totally cool. Lexie also still thinks that Mark thinks she is a freak, but in a drunken moment April finally tells her that Mark clearly is still in love with her. Lexie looks rather pleased with this idea, but when she goes to find him, he's about to embark on a couple of quality hours in the on-call room with none other than Amy.
And finally, everyone faces up to some hard truths that they'd all rather not talk about, for instance: April is a virgin, Alex is afraid of the elevator, and Teddy has a pattern of only picking unavailable men. While the Chief helps Alex by riding in the elevator with him until he is bored rather than scared, April and Teddy are still on their own for now.
Meredith and Derek are asleep when there is a knock at the door, and it takes a while for Mere to wake up and realize what's going on. Cristina has shown up like the ghost of trauma present and says that Owen is at work before reconsidering and apologizing for being there. Mere of course tells her to come in, and Cristina only hesitates over the weirdness of Derek being in bed too for a moment. He's dead asleep and so has no idea that she has crawled into bed on the other side of his wife. As they drift off, Mere VOs, "Most surgeons grow up being freaks. While other kids played outside, we holed up in our rooms -- memorizing the periodic table, huddling for hours over our junior microscopes, dissecting our first frogs." The next morning, Derek rolls over and takes his wife's hand, but after a moment realizes that he's already curled up next to his wife, and that the hand in fact belongs to Cristina. Thoroughly weirded out, he just rolls back over to his safe side of the bed.
Later that morning, the attendings are all gathered for a meeting with Perkins, whose time of sitting in the conference room and looking either "serene" or "serene with a cocked eyebrow" is coming to a close. He says that the few docs not cleared yet for surgery will be handed over to Dr. Amy, who will take care of clearing them herself. I am quite excited at the idea we'll get to see her again on the show -- she's always one of my favorites. Derek asks about Cristina and Richard jumps in lest we think that Perkins can actually speak complex sentences. Seriously, I was excited for another hot doctor but he just basically nodded with the same facial expression, asked a couple of questions, and dated Teddy for his entire three episode arc. Richard explains that Perkins thought Cristina should be assigned to something "low stress," such as administration. Derek's pretty aghast at the idea and instead demands to have her put on his service, pointing out that if she moves to admin she'll just leave the program forever. Various doctors throw out various opinions on the matter until Perkins reminds everyone that she "crawled under a table in the OR two weeks ago." I would argue that that wording implies that she meant to do what she did out of cowardice, and I'm surprised he didn't say something like, "Had a severe PTSD episode" instead, as she didn't crawl so much as she collapsed. Regardless, Derek finally shuts up the arguing by announcing dramatically, "She goes, I go."
Outside in the hallway, Meredith is watching all this with a furrowed brow and tells Cristina she thinks they are arguing about her, saying more to herself than her friend that they can't kick her out of the program for being traumatized. Cristina is just lounging against a wall and says she doesn't care what happens. Neither girl is happy, though, when Derek comes out and tells them that Cristina is on his service that day -- Mere because she just got bumped, and Cristina because she doesn't actually want to do anything.