The echo doesn't show anything. Chase and Cameron start thinking of other things they could check to see whether they can find whatever's producing the clot, but then Joe goes into tachycardia and starts bleeding out of his head wound. While they struggle to save him, Foreman freaking stands there looking at his nails, and comments that House did a great job thinning Joe's blood. As Joe's situation becomes more dire, Foreman starts laughing out loud, and Cameron yells at him to leave the room while Chase just looks horrified. So does the rest of the medical staff in the room. "Am I the only one to find this funny?" Foreman asks. He is.
When we come back from commercial, Foreman's stuck in a quarantine room. The only one in the hospital, it seems, since Joe is stuck in there with him. Foreman insists that he isn't sick, but House very seriously says that a guy bleeding out of a head wound isn't funny, unless you've got a brain disease. And since Foreman will be staying in there until they figure out what's wrong with him and Joe, he might as well try to make friends with his nemesis. On the bright side, House says, they now have a way to do the MRI. Foreman laughs that they blew up the machine. "Not the portable one, Chuckles," House responds. Foreman's smile vanishes. House gives him a thermometer and orders him to take his temperature while everyone else tries to solve his case. Foreman laughs again. I have to say, I'm not a fan of the "one of House's team members get a mysterious illness" storyline. I was hoping this show would have saved it until a later season when they were desperate for ratings. But maybe this will play out better than I think it will.
When Chase and Cameron come into his office, House is just finishing withdrawing his own blood. He tells them to do the same, and says that anyone with a high sed rate that indicates an infection will be joining Foreman in the isolation tank. No one looks particularly worried about their own health, though. Me, I'd be so far away from that hospital that I'd probably end up getting some crazy exotic disease in Africa or wherever the furthest point from PPTH is and die anyway. Cameron thinks that Foreman should be with them trying to figure this out, because she apparently wants to get sick. Either that, or Foreman's downturn in healthiness has made him an attractive prospect for the Widow Cameron. House says no, and concentrates on the MRI films they got from Foreman. They notice a "mushy" spot in his brain that explains his euphoria and also sounds pretty bad for Foreman's future in the healthy brain department. Cameron maintains that Foreman should be here with them, since they're dealing with a neurological problem, and Foreman is, after all, a neurologist. He's also suffering from what appears to be a contagious illness, so shut up, Cameron. House won't relent, and tells them to test Foreman's blood for toxins. He's thinking that Foreman caught something nasty from Joe's home given that they haven't gotten sick. House then asks the Cottages which one of them will volunteer to go back to Joe's apartment to find out what's there that's killing everyone. Chase sure as hell isn't going, so Cameron says that she'll do it and starts heading out. But House stops her, saying that Foreman got samples and brought them back, and they can test them at PPTH. This draws an angry response from Chase, who wonders whether House asked them to go back to Joe's apartment as some kind of test. No, House says, he just needed to burn off a few minutes to stretch this episode out into two episodes. This also explains the MRI scene. Cool as it was, it was also filler.