Previously: Cristina couldn't get over her PTSD from the shooting, so she quit being a doctor; Mandy Moore died on Bailey from a post-op infection; Kepner went totally bonkers during Hunt's trauma training, which kind of impressed Alex, probably because she reminded him of Izzie, who is totally the writers' model for Kepner now; Derek decided that finding a cure for Alzheimer's is the next crusade which he will pursue to a degree that he'll become totally insufferable; and Arizona left Callie at the airport after a hasty and clumsily conceived effort to give Jessica Capshaw some maternity leave.

Meredith's voiceover metaphor of choice this week is "pressure," and unless something interesting happens on that front -- say Mere taking the Freddie Mercury part while Bailey does the Bowie on a duet of "Under Pressure" -- I trust you'll agree that we shouldn't address it again, right? So while Mere VOs, Cristina watches TV surrounded by unpacked boxes in her and Hunt's new apartment; and Alex deals with his broken-down car by the side of the road. Later, all the docs are in the auditorium while Altman gives a post-op conference on that old-man lung-transplant patient from last week. Alex stumbles in and Mere, Avery, and Kepner speculate on what he was doing that has him smelling like a boozebag this morning (Alex: "What happens in Vegas..."); Avery is also fretting because he hasn't get been but on any attending's service, and he thinks it's because he's had a a few screwups lately. Mere tells them all to shut up when Altman gets to the part about Cristina. When Altman's ultimately forced to admit that Cristina isn't here to answer questions about the patient, Mark kind of flips out and starts asking everybody who might be in the know why. Mere can't say, Altman doesn't know, the Chief gets a phone call and leaves the aud, and Derek is too bust peppering Altman with accusatory questions about why she put Cristina under such a pressure-packed situation. Altman defends herself, saying that the initial request was simply for Cristina to watch a patient while she went and retrieved some lungs, and besides, are they here to do a patient presentation or a post-mortem on Yang? Derek, as snottily as he can muster, tells Altman, "Well, you saved the patient." Yes, um, HER JOB. Gosh, the more things change, the more I hate goddamned McDreamy.

It appears that Callie is in a hotel room (her old apartment is being sublet), living in depression and squalor. She jumps at the ringing phone, only to be bummed when it's Mark, asking what she knows about Cristina. From the looks of the "She WHAT?" reaction, it's safe to say she hadn't heard.