In the main case, the team deals with a fourteen-year-old girl who collapsed at her birthday party. She seems nice at first, but her story quickly goes through beats including pregnancy and a secret trove of rape-and-animal-themed pornography. She eventually turns out to have Dissociative Identity Disorder, which you might also know as Multiple Personality Disorder, or Split Personalities, or even "that thing Sally Field had in that one movie, not Gidget, later than that." So some of her personalities have different allergies, which caused understandable problems with the diagnostic process. Anyway, she's got cancer, too. So there's that. But at least she's not actually pregnant!
House mostly ignores her, because he's more interested in diagnosing a boy who died at four years old. This is tricky for him because Foreman has explicitly barred him from doing so, so he has to go through a lot of ridiculous shenanigans to meet with the boy's father and spy on the mother and so on. The whole time we're supposed to pretend that House might go back to prison if he gets caught, but that seems like more of a sweeps-week thing. The boy died of a genetic condition, which is the only thing that the mother would care about because she's very interested in moving on with her new life, new husband, and new son.
Finally, in intra-team news, Chase is somehow more interested in personal grooming than usual (I know, right?) and it's because he got a chance to appear on a local talk show as a ridiculous Australian stereotype who gives medical advice or something. It's relatively short and pointless, but at least the clip of Chase on the show is pretty funny.
House is at his computer, researching Air Force bases. He claims that he's going to go hang gliding at a place where Park says is completely flat. So that's another personality trait they've given her: encyclopedic knowledge of military installations. Chase is not there, for reasons that will become apparent, but not in any way interesting. Foreman enters to offer a case. His is a fourteen-year old girl, but House is more interested in a four-year-old boy he learned about somewhere. Foreman turns to go, but Adams has read the file and says House's patient is dead already. Foreman drops his file on House's desk and leaves. House glares at Adams and tells her, "Death is a consequence, not a symptom. If it's not a symptom, it's not relevant." Taub suggests they try to save things, including the girl and House's freedom. House hands him Foreman's folder and leaves.
The team (minus Chase) studies the case of the fourteen-year-old girl. I know how old she is because she got sick at her fourteenth birthday party. Chase enters and Park demands to know his dentist's name on the grounds that he must have just been there. I enjoy watching her act like House because it comes off as much more hostile when she does it. Adams and Taub throw around random diagnoses while Park determines that Chase didn't really see his dentist that morning because he got a fresh manicure. Who says you can't do both at once? Park says that Chase has had three haircuts since she's known him, but for some reason he's lying about getting a manicure. So why, she wonders, is he being cagey about this particular element of personal grooming? They decide to check the patient for opioids, meaning drugs.
The kid tells Adams that she sometimes takes vitamin C but is otherwise drug-free. And she had her attack while she was opening a Magic 8-Ball. Those things are possessed by the devil! Outside the patient's room, Taub tells the mother that "certain drugs" could explain the reaction. The mother says Iris (that's the kid's name, which is good to know because I was just about to start calling her "Fourteen") has been moody lately, so she's been spiking Iris's vitamin C with Diazepam to calm her down. Taub thinks the anti-anxiety medication could explain it. So they'll just get her off them and everything will be fine! And just then, Iris vomits.