Carter comes back into Mrs. W's room with an IV supplement bag and hooks it up, telling her that it should take about twenty minutes and that she'll start feeling better in a couple of days. She nods, and Carter asks Asthma Guy how he's doing; AG reports that he's feeling much better. Carter starts to say something else when he hears Mrs. W gasping behind him, and when he asks if she's okay, she chokes out, "Hard -- hard to -- breathe!" Carter listens to her chest and asks if she's having chest pain; she says no. He asks if this has ever happened to her before, and she pants, "When I -- when I got -- Bactrim." "Bactrim?" Carter repeats, and Mrs. W wheezes that she told Carter she's allergic to sulfa. Carter jumps up and examines the IV bag, then rips the IV out of Mrs. W's arm and rushes over to a cabinet to prepare an epinephrine shot as Mrs. W continues to puff and pant. He calls over his shoulder for Mrs. W to lie down; AG asks if Carter needs some help, and Carter finishes preparing the shot and says shortly, "No, everything's under control," and whips the curtain between AG and Mrs. W closed before administering the epinephrine. Malik bursts in a second later: "What happened?" Carter dissembles, but Malik says, "Somebody hit the call button!" and Carter points in AG's direction as AG pipes up from behind the curtain, "I did!" Malik asks why, and AG points at Mrs. W: "She was having trouble breathing!" Chen comes in through the other door and also asks what happened, and Carter lies that Mrs. W had an attack of hives, so he administered a subcutaneous epi. Malik asks where all the blood's coming from, and as we see a shot of the trickling wound on Mrs. W's arm, Carter says disingenuously, "Look at that -- she must have pulled out her IV." Chen asks why Mrs. W would have done that, and Carter yells, "How the hell would I know that?" and although he tries to temper it with a smile afterwards, his cover is basically blown; Chen takes a step back and eyes him suspiciously. Carter keeps up the phony chuckle for another second or two; Malik gives him the stink-eye. Carter tells Malik to start another IV and give Mrs. W antihistamines, and he listens to Mrs. W's chest and tells her in a falsely confident voice that she "just nodded off for a second there" before reporting "good pulse, good respirations" and preparing to flee the scene. Malik adopts a "whatever" tone and asks Carter's disappearing back if he wants to order fluids, and without slowing down, Carter tells Malik in a strangled voice to give her a liter over an hour. Chen watches him leave, and turns to Malik to say something . . .