Alex walks into Izzie's room to find her going over the IL2 schedule with Swender and Cristina. It takes him a few moments to catch on, and Izzie has to tell him she's not doing the surgery. The doctors realize they need a moment and walk as quickly as possible out the door and then Alex shuts it to yell at Izzie that she's having the surgery. When she asks what happened to it being her decision, he yells that he only said that because he thought she'd make the right one. It's oddly comforting to have old Alex bust through like this, probably because, although he's infuriating, he's doing it out of love for his new wife. He yells at her that now that they are married it's his life at stake as well as hers, and informs her that she's having the surgery. She shuts her eyes and sighs, already forgetting that she just ordered him to tell her what to do. I have found, somewhere, sometimes deep, deep in my heart, a little bit of sympathy for Izzie but it's really only a little, and this isn't one of those times.
Derek has pulled Cristina into a conference room and is reading her the riot act for talking Izzie out of the surgery so much that she can't get a word in edgewise. Unlike last time Cristina was in trouble, however, Mere runs in and rescues her, telling Derek that she's the one who did it. Derek's shoulders slump in the realization that once again his fiancée has infuriated him. Cristina takes her leave and suggests an apology but Derek's look sends her out the door as-is, and he then shakes his head. Meredith reminds him that she saw what happened to her mother as she disappeared and lost her memory and her dignity as she declined. Derek isn't terribly sympathetic and argues that Izzie isn't her mother and has a treatable tumor, so she can't make this personal. He then orders her in no uncertain terms to go back and change Izzie's mind as a doctor, his resident, rather than as a friend, because her tumor could kill her.
Hunt then finds Cristina and pulls her into a supply closet for a "consult." Sadly it's a less sexy "consult" than happens most of the time when one doctor pulls another into an empty room. He excited tells her that he's figured out what's wrong -- he hasn't gone to see his mom because a part of him is still in Iraq, and that he hasn't fulfilled his commitment to his unit. He would still be there if not for what happened to his unit and so he has unfinished business which is why he can't move forward with Cristina or anything else. For someone who seems to have come far with his therapy, it seems awfully dense for him to think that his PTSD might get better if he goes back to the war zone. On the other hand, though, he could really believe that facing it head-on could help him get over it. She's totally stunned as he concludes that he has to go back, and then he's stunned when he realizes she's not jumping for joy at the prospect. He asks her for her support, but she informs him he doesn't have it, and she walks out.