The next day, Foreman shows Lupe the crack pipe he found when he broke into her apartment. She denies it's hers and coughs. Foreman ignores her constant coughing to make it very clear that he thinks she's a crackhead who got arsenic poisoning. He takes some of her hair out to test for arsenic. Suddenly, Lupe's coughing blood. She goes into respiratory arrest.

When we come back, Lupe is breathing again and on her way into the MRI of DOOOM! Chase and Cameron are monitoring it, which can't be good for anyone. They at least manage to tell us that Lupe's hair only had trace amounts of arsenic in it, so that isn't what's making her sick. She may want to keep crack pipes out of her apartment in the future, though. Or at least hide them better. Chase begins the MRI and tells Cameron that he's available tonight if she changes her mind about seeing him. Cameron turns the invitation down forcefully. She says she doesn't want to do anything with Chase except work. And even then, Cameron rarely wants to do it. Chase tells her to chill out; he's just saying he's available, and he's going to be doing that every Tuesday from now on. No big deal. And then he goes back to work. But Cameron doesn't want to work anymore. She tells Chase to put her behind him. He points out that she's the one bringing it up now. All he's doing is reminding her once a week that he's interested in her. Until, hopefully, he moves on and finds someone who actually likes him. Cameron doesn't know what to say to that. Chase finds a mass.

A biopsy shows white blood cells where there aren't supposed to be any. Cameron says that this suggests an autoimmune disorder. House wants her to get specific about what kind of autoimmune disorder, while Foreman just wants to treat her with steroids, since, Foreman says, all autoimmune disorders are treated with steroids. He provides several examples of this, one of them being "lupus vasculitis." Okay, does that really exist? Is it possible that the two diseases it never is on this show have now come together to form one super-disease it'll never be on this show? That's awesome. Foreman makes his point, and House sends them off to start Lupe on steroids. As for House, he's too busy tonight to do any follow-up with Lupe. Of course, Cameron wants to know what House is busy with. "Wilson's got a date tonight," House grumbles.

I thought (hoped) House would be off getting in the way of things at the art exhibit, but instead, he's made an appointment with Wilson's ex-wife. She shows him a condo he's pretending to be interested in, and he asks her if it's in the same neighborhood where she and Wilson had their first date. Ex-Wife is amazed that House was actually paying attention to that. He wasn't, actually; their first date was in Boston. Ex-Wife tries to show House the all-granite countertops while House pumps her for info on what it's like to date Wilson. Like he doesn't know.