"It wasn't the flu," House says, but he doesn't look very happy to have finally solved the mystery; "it's what she did for it. She has amantadine poisoning." I guess those pills were prescribed to her by the same guy who put her on those prescription diet pills. That guy needs to stop prescribing heavy-duty medicines for tiny problems. Wilson figures out the rest: when CTB's kidneys were shut down in the bus crash, she was no longer able to filter out the amantadine, causing her to overdose, which affected her heart, liver, brain, etc. Wilson says they just have to put CTB on dialysis to get rid of the amantadine and she'll be as good as new, but the look on House's face suggests that it's not going to be that simple. Plus, we already know (and Wilson apparently forgot) that CTB has been on dialysis since she was brought into Craphole General. Sure enough, House explains that amantadine is a little bastard that binds with proteins and therefore can't be filtered out of the blood with dialysis. "There's nothing we can do. I'm so sorry," he says, and the sad music comes back but I won't be sad! We have fifteen minutes left in the show so obviously House is going to figure out a way to save CTB. Happy ending surprise! Yay! In the flashback, CTB is still sitting on the bus, blissfully unaware that she's just taken a dose of poison and of the bus crash that's about to happen. In the present time, House is crying. Not because he's sad about CTB, I suspect, but because of his own guilt and possibly because he actually has sympathy for Wilson, something I didn't know House was capable of until now. Then the bus crash happens again, and House in present time has a seizure and knocks over medical equipment but I'm sure that's one of those good seizures that helps you think of ways to cure amantadine poisoning.