Kumar and Thirteen follow House with guesses as to how those bad blood fragments got in Jimmy's blood. Thirteen guesses "hemolysis from the malaria meds" they gave Jimmy for the malaria he doesn't have. Whoops! House tells them to shush, as he's already figured it out. He finds Jimmy's band hanging out in the hallway and checks their arms for track marks. He finds them on one guy and dumps out his jacket. There's a needle. Before Thirteen can say she's sure the guy was using it for diabetes, House says the guy shared his needle with Jimmy, getting his blood in Jimmy's and causing the blood fragments and the clotting. Also, a touch of hepatitis. And AIDS. I know they're heroin addicts, but there's no excuse for shooting up without protection these days. The clotting and the blood fragments are not, therefore, symptoms, and they'll have to start over again. House tells them to throw Jimmy's bandmates out and strap Jimmy to the bed. Kumar shouts that Jimmy isn't in his bed right now -- he's on the floor suffering from respiratory failure. Thirteen and Kumar help the guy while House stands over them and tells Thirteen that she's in luck -- this is definitely not because of drugs.
After the break, the team is hiding from Foreman in the laundry room. House tells them to cross clotting and bad blood fragments off their list of symptoms and add respiratory failure. CTB immediately guesses inhalants. Did she not see Thirteen's extra-credit points on the Whiteboard? Time to step away from the drug-related diagnoses, CTB. House rolls his eyes and says if he wanted a drug diagnosis for the sake of a drug diagnosis, he'd have told Foreman where they were. Too bad Foreman was waiting for just such a statement to make his grand entrance. He's been hiding behind the industrial-sized washing machine this whole time, having cleverly followed PS, who in turn followed CTB. Not because he was trying to find House, mind you, but to look at her ass. PS guesses an infection, to which House waves the negative results of a lumbar puncture around. But who ordered the LP? Thirteen did, hoping to hedge her bets by testing her bacterial meningitis theory. I guess she wasn't that confident about malaria after all. Bacterial meningitis, by the way, is VERY contagious. If she had even the slightest suspicion that Jimmy had that, she really shouldn't have let him hang around a bunch of children with compromised immune systems.