Dr. Owen Hunt, the military field surgeon, is back at Seattle Grace, where he's been named chief of trauma. He leads a "skills lab" to help surgical interns and residents learn how to deal with trauma cases. He draws back a curtain to reveal several anesthetized pigs -- each of whom he then stabs! "Go ahead, save their lives," he tells the shocked group. "You're a monster," Izzie says and marches out.
Izzie won't work on the pigs, but she has to work with Hunt, who spends all day informing her of the many medical advances based on animal experimentation. She angrily tells him, "You are torturing animals in an age where we have the technology that no longer requires us to. You want to do that, go ahead, but don't tell me I'm less of a doctor for walking away."
Richard encourages Miranda to do another headline-grabbing surgery, this one on a little girl with an inoperable tumor. Meredith finds her old "Anatomy Jane" doll, which comes in handy in showing the 10-year-old girl where her tumor is, and for the surgeons, when figuring out how to remove all of the girls' affected organs at once -- and still keep her alive.
The mother insists on having Erica in on the surgery, but she points out that three other hospitals have turned down the case as too risky and calls it "a huge waste of resources." She finally agrees but maintains a negative attitude.
The surgery is a success and when Richard praises the team, Miranda chews out Erica for taking any credit: "You may be a fine surgeon, but today you were a pain in the ass. You made it as hard as humanly possible. We did a great job today, but that is thanks to me."
Cristina, who's been trying to avoid Owen because he kissed her, is insulted when he can't remember her name, and when he criticizes her pig-saving technique as not being "quick and dirty" enough. When a real trauma rolls in, Cristina is stuck with saving all four pigs. She discourages her interns from nicknaming the pigs. "They're not pets, they're subjects," she reminds them. But she gets emotionally involved when "Wilbur" crashes and she has to operate to save his life. When she runs through how she saved each pig to Owen, she refers to them by the names the interns gave them. Owen tells her "Good job," and then tells her to "terminate them." "If you want them dead, you're going to have to do it yourself," she tells Owen, but Lexie, who also bonded with the pigs, urges Cristina to end the animals' suffering as they'd all be facing painful recoveries.
Owen admits he remembers Cristina, but that was "before" his entire unit was wiped out and he's now living in the "after."
Derek and Mark show up to help with two accident victims but Owen tells them they're not needed. "My residents aren't going to learn anything if they stand back and watch attendings do it. Unless that attending is me."
"Rambo's completely out of control," Derek complains to Richard, who tells him he's got more important things to worry about.
Alex admits that usually he'd page Derek to deal with a lacerated scalp, but Owen advises him to do it himself. When Derek inherits the patient, Alex has to explain why he used skin glue on the patient's wound: "Owen says that 'the ER is like a war zone."' "What qualifies us as a war zone?" Mark wants to know. "Our undermanned gift shop?"
Mark and Derek take issue with Owen for nearly maiming the guy with the skin laceration. Owen doesn't apologize, but asks them to teach him any medical procedures he might not know.
Izzie is upset that Alex asks her, after a week of sleeping together, if she minds if he sleeps with other women. She tells him he's an "ass," but finally realizes that this is his way of asking her to be monogamous, and she happily accepts.
After an amazing session of sex with Callie, Erica exclaims that she's "So gay!" which sends Callie running off to Mark to have "plain old, missionary, boy-girl" sex. When she has trouble figuring out why there isn't more of a difference between sex with him and Erica, Mark tells her that the difference is that he knows she's sleeping with Erica, but Erica doesn't know Callie is also sleeping with him. Callie confesses the cheating to Erica, explaining she might never be "women-only" and Erica says, "Okay."