I've been watching this show since it began, and I've never felt (as some do) that it's "jumped the shark" or suffered a slow decrease in quality. Every season has had some good episodes, some not-so-good ones, and one or two jewels. "House Divided" came out of nowhere to dominate the latter category. The reason this episode is so much damn fun is that the unthinkable happens: House finally "cracks." Just when it seemed like this character was hopelessly static and would never really grow, the writers faced facts and admitted that a guy, no matter how smart, who tried to live his whole life as a completely rational being and ignored all emotion would never succeed at it: he'd either cave or go literally crazy. House refuses to cave.
All of the show's best elements are in this episode: a cool medical mystery with a red herring, an interesting patient and the ethical issues surrounding his treatment, great lines ("and then I have a clever response"), pure hilarity (House rocking out to Public Enemy is definitely a crowning moment) and House dangerously abusing his body in the name of science (in this case, going without sleep for days on the grounds that it's "interesting"). But at the same time, all of the standard elements are subtly warped. As House, the central cog, becomes inwardly unglued, so does the whole formula: nothing is working correctly. House breaks a major rule in his treatment of the patient, but for the first time ever, he can't explain why he did it. His analysis of the patient's mother's motivations is totally off base. The patient doesn't grow personally; no lessons are learned. The team spends most of the episode mildly drunk. Wilson is even more ineffectual than usual and ends up wandering into the street hammered and without his pants. Cuddy has the upper hand. Even the MUSIC is screwed up: the cool percussive beats that are always in the background suddenly morph into what I can only call "the world's creepiest sound effect" in the scene where House relaxes in the bathtub (when he realizes that whatever is happening to his brain is worse than mere sleep-dep... *sigh*, beautifully done). I also note that the lighting gets increasingly brighter throughout the episode as House gets increasingly spaced-out.
The whole thing is simultaneously one of the funniest, saddest and scariest TV episodes I've ever seen. The two follow-up episodes were good, but they couldn't match the "House" meets "X-Files" meets "Twilight Zone" vibe of this one. A great way to wrap up the season and proof that the show has life left.
