House and Hadley prepare to fire their spud gun. The fair-like environment of the competition reminds Hadley of the county fairs her father used to take "us" to. House asks Hadley who the "us" she's referring to is. Hadley says she meant her and her mother, but that doesn't really make sense what with Hadley's mother being stricken with Huntington's for almost all of Hadley's childhood and thus not really able to attend or enjoy county fairs. House figures out that Hadley must be talking about a sibling she never mentioned before and that no one else knew about. Even though she was in a serious relationship with Foreman and PPTH has, like, every personal detail in its employees' files. Oh, and we've seen flashbacks of Hadley's childhood and a sibling was never in them. But now that the writers had to come up with a reason for her to leave the show for almost an entire season so their precious star could shoot some movies, Hadley has a brother. And the fact that she accidentally mentioned him now after years of pretending he didn't exist (because he didn't) leads House to realize that the man she killed was her brother, who also has Huntington's. Wow, that's quite the unlucky family Hadley has there. Three out of four of them have Huntington's! Then again, it's entirely likely that she has like five other siblings she never mentioned before who don't have Huntington's. House guesses the guy she kneed in the balls was her brother's doctor, who wouldn't help her cover up the assisted suicide. Hadley admits that House is right about everything but the doctor. The guy she attacked had nothing to do with her or her brother; it was her cellmate's boyfriend who cheated on her while she was in jail.