After the commercial, Foreman has the fastest-spreading case of Legionnaires disease ever and he is not happy about it. Cameron makes a very stupid comment, and Foreman insults her for it. She tells him not to be nasty, and he whines that he's in pain, so everything he says is totally excusable. Cameron points out that House is in pain, too. "And he's a delight!" Foreman says. "He doesn't try to kill his colleagues," Cameron points out. Eh, I don't know about that. He's certainly tried to embarrass Wilson to death more than once. Foreman's thermometer dings, and he shows the results to Cameron, who's pleased to see that his fever has gone down a degree since the Legionnaires started. Foreman isn't very pleased, though, and just makes his cranky old man face. But he has to admit that the pain isn't any worse than it was before.
Wilson stops by House's office, even though every time he does, he gets yelled at. House tells him that the Legionnaires has slowed the disease down, which he's hoping will give Steve more time to get sick. Wilson asks what House will do if Steve never gets sick, and that gives House an idea.
He strolls up to Chase and Cameron, and asks Cameron which diseases affect humans but not rats. "Why are you asking me that?" Cameron asks. "Because I'm sure that you spent the first twelve years of your life dreaming of being a vet," House says. Cameron does not deny this. Then again, you'd be hard-pressed to find a little girl who doesn't want to be a vet. Unless, like me, she's allergic to cats and dogs and, therefore, has to have a rat for a pet. House is asking because Steve hasn't gotten sick, and neither has Cameron. Chase says that there are some bacterial infections that can affect humans but not rats. Cameron says Foreman tested negative for every bacterial infection you can find in a brain. So now, House says they're looking for bacteria that doesn't affect rats and doesn't show up on tests, because the body won't make antibodies for it. It also explains why Legionnaires disease had a positive affect on Joe and Foreman, since it prompted the body to make antibodies that also fought the mystery illness.
"The answer is Wisteria," House tells Foreman, who's looking pretty close to death. Oh, I'm sorry, House said Listeria. Wisteria just revives your dead acting career, but then makes you go on talk shows and say stuff that you probably shouldn't that kind of makes you seem like a maniac. And you have to make out with Ryan Seacrest. It's a very awful disease. House wants to treat Foreman for Listeria immediately, but, unfortunately, the medicine for it will also cure the Legionnaires disease. So if House is wrong, the pain will come back as the disease continues to progress. House refuses to answer any of Foreman's questions that are based on him being wrong, and puts the drugs in the airlock. Foreman doesn't want to take them. He wants a white matter brain biopsy, hoping that they'll find the disease there. House refuses, although not for the reason you'd expect him to, which would be something along the lines of Foreman only having black matter in his brain. Instead, he says that white matter brain biopsies have a tendency to turn the patient they're being performed on into something like a "retarded child" or a "small animal." Steve McQueen is a small animal and he seems pretty okay to me, so I guess that wouldn't be so bad. Foreman agrees; he wants the biopsy. House refuses, saying that spending your life being disabled ain't that great, even though he does make it look "oh-so-sexy." He's being sarcastic here, but there are several people in the forums who would beg to differ.