Everyone knows the rule that the Black character dies first in a horror movie, but a 2013 study of 50 slasher films with at least one speaking Black character found it happened in only 10 percent of them. That self-mythologizing trope opens a deep dive into the anatomy of the slasher: a strict, almost ritualistic formula built on a past wrongful action, an anniversary that reactivates the killer, and a human antagonist stripped of ordinary morality. We trace the genre's lineage back through the 19th-century French Grand Guignol theater with its bursting blood bladders and manipulated lighting, Agatha Christie's Ten Little Indians and its corrupted nursery rhyme, and the twin 1960 grandfathers Psycho and Peeping Tom, which introduced the killer's point-of-view shot.

The conversation follows the genre's international evolution through German  ...