This, you see, is what the Seep is about in this slyest of social satires. The Seep breaks down hierarchies and obliterates norms, makes everything possible, abolishes death and pain, and recasts humanity as an infinitely plastic proposition. “The Seep did love us,” the book’s elusive narrator remarks early on, “and it wanted to help us to create a perfect world. And this destroyed life as we knew it.” Chana Porter’s affectionate takedown of every modish leftist pretension is scalpel-sharp and oddly moving.