Triage training. Izzie is holding a patient's wrist, giving the bullet and her recommended treatment. Bailey asks her if that's it, and after a moment trying to read Bailey's face to see if it's the right answer, Izzie says yes. Callie's holding a stopwatch and yells time, and none other than Sydney, playing the patient, sits up and announces that she's now dead, complete with a very dramatic, shaking, eye-rolling-back performance to illustrate just how dead. Turns out Izzie sent her hypothetical patient home too soon, and Hypo got septic and died. Ever professional, she rolls her eyes. Although honestly, if I had to spend more than 30 seconds with Sydney, I would be too, so I can't knock her for it this time. Bailey explains to them all that when it comes to triage, they have to be quick and thorough, and use their instincts. She calls Karev up to take his turn, and in a great throwaway moment, Sydney fluffs her hair. Could she be hoping for a ride on the Alex train? Bailey goes on some more about the importance of triage, which explains why they're just getting to their training now, months (we think) into their residencies. She also mentions that if somehow, maybe, they ever were to need to use this in a real life situation they'd have only minutes to take care of things. Callie jumps in to tell them they'll be tested on it later and there are some shenanigans with George not respecting her as much as she'd like as his boss. After she gives him a talking-to, the Chief walks in. There's an emergency situation, and he'll need to send a team out into the field. Oh, sweet unexpected heavens, this means they're probably going to have to put their triage knowledge to practical use!
Cristina asks if this is part of the exercise. "Are we supposed to act appropriately... tense?" She's good at tense, but it turns out she gets to try it for real since the Chief says it's an actual situation. He doesn't know where or what happened, just that they got orders to send doctors. They all put on big nifty jackets and gets bags of supplies ready. Cristina comes up to Meredith, tentatively telling her she has news, but Mere just asks if she's pregnant again. "'Cause I can't handle the extra months of bitchiness." Cristina begins to answer, but they're all hustled outside to the ambulance that will be their ride. Once there, it turns out there's only room for five, so Bailey tells Cristina to wait, even though Izzie was the one who was flippant. As she jumps into the vehicle, Meredith finally genuinely asks Cristina about her news, but it's not the time and they have to leave. Cristina is left, forlorn and alone, as they pull away. At this point the producers decided to grab some music video/soap opera, stylized slo-mo b-roll showing the ambulance dramatically driving the mean streets of Seattle.