Once he arrives he finds Alex with Derek in the control room and thunders at the resident to get the hell out. Derek is confused and Callie explains that he and Lexie hooked up once when she and Mark broke up. Derek looks for a second like he's about to mention that it's been more than once, but winds up keeping quiet and Mark gripes that you don't sleep with another man's girl. He saves himself from being totally, absolutely hypocritical by adding that he learned that the hard way, and Derek congratulates him on the save. There's more banter about him sleeping with the nurses and Derek actually looks surprised at his buddy's actions -- apparently becoming Chief sucked all of the common sense and previous knowledge of his lifelong friend right out of his head. Mark claims he can sleep with whomever he wants and when Derek protests, Mark asks if he's going to fire him. Callie breaks into the pissing match to focus on the task at hand and as soon as the scan is up, Mark comments that the woman is deaf. Derek and Callie are amazed at how he could guess that, and Mark explains that she's got extra bone growth in her ear that he can take out super easily when Callie is done with the knee surgery. It takes Derek a few moments to really wrap his mind around his slutty friend's statement but Mark reminds him, "I'm that good," and then asks if Derek really wants to fire him. Callie is fed up with the silly man-fighting because she is a woman and we can all see that this is ridiculous and they should just whip out rulers already, but Derek just smiles.
Keeping up Seattle Grace Mercy West's reputation as the least professional and appropriate medical institution around, Jackson has been allowed to stay in the OR and watch his grandfather's surgery despite the rule about family. Richard is making chitchat like it's no big thing that Harper is checking out his own intestines, and Harper asks Mere if he can ask her a personal question. When she agrees, he asks, if Ellis was still alive, would Mere have chosen to study somewhere else that wasn't as high quality just to avoid the "advantages of her legacy?" Mere knows a trap when she sees it and stalls, while Jackson jumps in to ask Richard a question about a particular method he might use during this surgery.
Up in the observation deck, there's general bitching by Cristina, Lexie and Alex about Jackson's being allowed to be down there and Harper's personal request for Mere to join in as well. Alex decides that a quickie might help his mood but when he tries to convince Lexie to go grab "a bite" she tries to shove him off to prove to nearby Cristina that she doesn't have feelings for him. It doesn't entirely make sense because if it's sex without feelings as she insists, she could just... go have sex, but I guess she's trying to cut it off completely for now and Alex is miffed. Charles then walks in to provide his usual few seconds to the episode -- Cristina bitches at him for blocking her view and then mocks him for letting the daredevil die. Charles takes immense pleasure in reporting that the guy didn't die and that Charles personally got his heart function back so that now he's an organ donor. Before you can say "shady maneuver," she bolts from the gallery as Derek comes in to watch. At that moment below, alarms start to ring and Richard tries to keep Harper calm while he figures out what is going on.