Sir William screams in pain. He says his legs feel like they're on fire. They're not looking so good, either. Better than his still-blood red eyeballs, though. House is called in, and as he downs some more ibuprofen (all I can think of when he does that is that he's going to burn a hole in his stomach! It happens!), Hadley says Sir William has rhabdomyolysis and kidney failure. Foreman says that means Sir William's problem cannot possibly be environmental. He seems annoyed, possibly because he and Hadley just stayed up all night trying to prove something that Sir William did in three seconds with his swollen legs. Taub is all about checking Sir William for cancer, but House just says they should check out Sir William's apartment. The symptoms fit an environmental cause, so he doesn't care what all of the test results say. Hadley points out that Sir William hasn't even been inside his apartment in weeks. "GO! NOW!" House yells, and walks away. "I liked him better when he was on Vicodin," Chase says. Yeah, because he treated you so much better when he was punching you in the face, Chase. Foreman sends Chase and Hadley off to do House's bidding, saying he and Taub will ultrasound Sir William's liver in the meantime looking for cancer.
Cuddy examines the individually-wrapped pastries bin in the cafeteria for like five minutes, as if she'd actually ever eat one of them, until Wilson strolls up. He can't help but notice that she's being a bit aloof around him, but she claims she's just "preoccupied." Wilson thinks House must have said something to her, but she denies it, apparently having decided that she's better off saying nothing to Wilson ever again since he'll tell it all to House. But Wilson persists, sitting down in a booth with her uninvited and launching into a discussion about himself and how he's nervous about getting involved with the woman who broke his heart twelve years ago. "You never know what can happen. Might as well give it a chance," Cuddy says with a tiny and joy-free smile. Hmm ... that sounds like the same advice she gave herself when she was trying to figure out if it was a good idea to sleep with her dad's best friend. But Wilson is too wrapped up in himself to care and just smiles.
The ultrasound shows a bunch of masses in Sir William's liver. Taub assumes they're cancerous tumors, but Foreman has him zoom in on one just to make sure. It explodes in a very un-tumor-like way. Taub and Foreman have no idea what it is except "not cancer."