Chase tells Brent that Michael's kidney damage is causing his potassium levels to increase to dangerous levels. If they can't get the levels back down, Michael will have a heart attack.
Kara hasn't had a seizure yet, and the biopsy Cameron did for myeloma was negative. Suddenly, Kara's EEG patterns start getting funky. But Kara isn't having a seizure; she's just making sucking motions with her mouth.
Cameron tells House that Kara is having encephalopathic delirium, which means that her problems have a real physical illness at their source. Which, House is pleased to point out, means that he was right, and Foreman was wrong. Again. Foreman doesn't mind. Meanwhile, Kara's brain is going to shut down completely if they don't find out what's wrong with her.
Michael's heart is giving out. Chase rushes over to save him.
House wants Chase back with them to help figure out what's wrong with Kara, as Cameron and Foreman try to come up with theories, most of which are the same ones they had before that were ruled out for various reasons. "Recycling sucks," House says. Unless, of course, he's the one doing it. House suggests Pellagra, due to Kara's alcoholism causing her to have a niacin-free diet. If they give Kara niacin, she'll be just fine. Chase enters the room, looking pretty grim, and tells them that Michael has died, so there goes Kara being fine ever again.
A nurse shuts down Michael's machines while Brent cries. Aw, I hate the dead baby episodes.
Foreman sits down next to Kara's bedside, who I'm assuming has been given a few doses of niacin and is looking much better. He asks her a few questions about who she is and when she was born. Kara only wants to see Michael, though, and Foreman explains to her that the voices she was hearing before were because of a vitamin deficiency. Kara starts to sob that she remembers "doing things" to her son and asks whether they really happened. Foreman says that they did. She tried to kill her son. Worse yet, she succeeded. Kara screams and cries and then throws up a ton of blood. That's some serious grief right there.
The bloody vomit is a new symptom, and not one that's consistent with Pellagra. Ugh, how many freaking illnesses does this woman have? Searching for all the correct spellings of them is tiring me out! Chase is too busy thinking about Michael and what he should have done to save him to pay attention to Kara's case, though, and House yells at him, telling him to get his head "out of the dead baby's butt." Thanks for that visual, House. It does give him an idea, though. House asks Chase how much polystyrene he gave Michael for the potassium, then runs out of the room.