Bobby Hatcher is a hockey goon. That means he beats people up in the middle of a hockey match. As far as I know, this is not a tie-in with the Seann William Scott movie. He contracts a mystery disease and also attracts the enmity of Taub, who thinks hockey would be great without all the fighting. And he hates bullies. As a result, much of the episode revolves around Taub making guesses that thinly veil his contempt. And then House mocks him for it. Eventually, Hatcher turns out to have Epstein-Barr, which caused mononucleosis. And Taub makes a friend.
Meanwhile, Wilson has been losing sleep because a neighbor has a noisy baby. This leads House to present him with a long-lost eleven-year-old son, which eventually freaks Wilson out because he's not ready to raise a child. But it was all a scam in which House hired a professional child actor. So, I guess, never mind?
Oh, and Park moves in with Chase. But there's no sex involved. Instead, Chase ends up playing cribbage with Park's grandmother. Saucy!