A kid with both male and female DNA whose parents chose to raise him (and have the appropriate surgeries) as a male without telling him about his condition collapses after making the game-winning shot at a school basketball game. Hadley the Bisexual immediately identifies with him, and after finding a possibly suicidal poem in his room, decides that he should know the truth about his condition. The parents are livid, as their son/daughter does not take the news well. Then it turns out that he has a terminal illness, and the suicidal poem was actually just a homework assignment to write in the style of Sylvia Plath. Oops! Hadley tries to make up for it by figuring out that it isn't the terminal illness after all, and then House finally figures out that it's just simple dehydration, the effects of which lingered longer than usual because of all the sports drinks s/he drank. When they gave him/her a contrast MRI at the parents' behest to look for a blind uterus (something that House assented to even though he knew it wasn't the problem), the kidneys couldn't filter out the contrast effectively enough and it spread all over his/her body, shutting down various organs as it went. S/he will be fine after some dialysis. Meanwhile, House is acting nice to people and even assenting to the patient's parents' demands, which makes everyone suspicious. Then he stops breathing during a nap in his office, and Wilson figures out that he's using heroin as a painkiller. He's wrong -- it's actually legal and doctor-prescribed methadone, and it's taken House's pain entirely away, so much so that he can walk without his cane. Cuddy refuses to let him work at PPTH while on life-risking methadone, though, so he quits(!), shaves(!!), and wears a suit(!!!). Wilson decides that his friend is finally happy, and that's worth possibly losing him to a methadone overdose, so Cuddy hires House back. Ultimately, it doesn't matter, since he decides to give up the methadone because it dulled his senses and made him agree to the MRI that almost killed his patient, and he'd rather be a brilliant miserable diagnostician than a pain-free and happy but not-so-special one.
We open in a dark hospital room. It turns out these were not the best conditions to deliver a baby, as the one the two new parents got has both male and female DNA. A doctor explains that the condition is called genetic mosaicism, and the baby should live a perfectly normal life as soon as they fix up hisher genitals. Mom, ensconced in darkness, asks for clarification on that point. "Made to look more typical," the doctor says. Mom is still confused, since she doesn't even know what the sex of her baby is. What part of "male and female DNA" doesn't she understand? The doctor says they get to choose. They might want to turn a few lights on before they do that.
And then it's twelve years later, and House kicks off March Madness a little early with a middle school basketball game. Our s/he baby is now a seemingly normal boy, although when he gets the chance to make a shot, he chickens out and passes it instead. What a girl! He gets the ball again and another chance to shoot, and just as time runs out, he scores the winning point. Every boy's dream come true! But stalling to make it come down to the last second like that did have a certain dramatic flair, so, what a girl! His parents cheer until their son doubles over clutching his stomach before collapsing on the ground.
House isn't even on this show anymore, so we go to morning at Hadley's apartment instead as she and Foreman get dressed for work. Hadley asks Foreman if she should wear boots or heels to work. Foreman says he's "a fan" of her heels, so she chooses the boots, saying that House probably knows that and they have to keep pretending they've broken up. Also, didn't House once refuse to hire someone awesome because she wore heels to the interview? Why does this not also apply to Hadley?
Amazingly enough, House is already at work, although he isn't actually working. He's having breakfast with Wilson, and asks for Wilson's leftover bagel. Wilson is flabbergasted; House has never asked him before taking his food before. "Yes we can," House says as Cuddy comes marching up with a new case. It's Jackson the boygirl, who has "persistent pelvic pain." "Fun!" House says, reaching for the file. Cuddy rains on his parade and says he's not allowed to tell Jackson about his female DNA problem, on orders from the parents. House says that's less fun, but he'll still take the case. He grabs the file and walks off, leaving Wilson and Cuddy to wonder what's up with his new attitude.