“Treehouse of Horror XXII”: Homer gets his arm caught in a boulder in an isolated canyon. He’s also paralyzed, but can communicate via natural gases. Mountain climber Aron Ralston provides his own voice. Meanwhile, Bart and Milhouse are in deep space, transformed into one-eyed avatars and caught up in planetary warfare after Bart falls in love. And Ned Flanders is transformed nightly into a cold-blooded vigilante.