Finally, Owen and Teddy greet the last ambulance, which contains a shot 20-year-old. The paramedic tells them that this is the emergency thoracotomy he'd called them about. Owen is aghast that the guy would do a thoracotomy in the field, but he immediately defends that he didn't do it. The doors swing open to reveal Cristina, covered in blood, her hand inside the dude's chest, and she tells the gaping surgeons that she had to crack his chest as if this is the most logical thing in the world.
Once inside, we get the standard, dramatic hospital television show shot of them wheeling the patient to the OR while Cristina rides along with her hand in his chest. Owen's not sure she should be doing this but Teddy points out that right now her finger is plugging the hole and Cristina assures him that she will be okay. He's skeptical, but as ambulances are coming in like ants at a picnic, he runs back to work.
Stark and Alex are working on their teenage patient to the revolting symphony of gurgling and sucking that the GA sound folks do so well. Stark, being the most incompetent doctor alive who would rather let a patient get disfigured or die than miss his dinner reservation or the like, decides her wounded leg needs to be amputated. Alex is shocked because he's sure Callie can fix it, and as he argues about what they could do right now to save it, Arizona comes up to the gallery to watch her replacement. Stark argues that her life is worth more than her leg (which would be true if the leg couldn't be saved) but Alex's pleas to not disfigure a 15-year-old fall on deaf ears. Stark angrily orders him to prep the leg and starts to put the saw together, so Alex calls up to Arizona in the gallery to, "Freaking do something!" I'm really having a hard time believing that Stark would not only continue to get hired places, but that he would be hired as the head of a department. Would he really have been able to pull the wool over people's eyes for this long? If so, I'm renewing my fear of hospitals.
Meredith and Derek prep the professor for surgery and when a nurse comes to inform them that the patient's wife has arrived, Mere goes out to find her.