“Weapons,” “Harvest,” and the Shackles of the Horror Genre

Horror is an accursed genre. Because it promises to deliver a specific sensational effect, its stories are obliged to fit into preordained patterns. Its popularity depends on predictability, and the task of providing the expected thrills renders the genre even more formulaic than superhero blockbusters. Zach Cregger’s new movie, “Weapons,” is, in this regard, an exemplary horror film—reducing social complexity and elaborate fantasy to a narrow outcome. The action starts at 2:17 A.M . on a week night, in a middle-class suburban neighborhood somewhere in Pennsylvania, when seventeen (of eighteen) students in a local elementary-school class get out of bed, leave their homes, and vanish. A voice-over narration briefly recounts the departure and sets up the subsequent investigations by police