A Synopsis, Without Spoilers of the Mice

Heinrich Kramer, the Dominican inquisitor and author of the Malleus Maleficarum, has built a life and a bestseller out of a single, unnamed terror: a boyhood night locked in a meat locker at Schlettstadt with a feral tabby, a fear he has spent forty years dressing up as theology. Expelled from Innsbruck by a bishop who dared ask for proof, Kramer writes the book that will make the question unaskable, and rides its fame south to the Rhine.

In the autumn of 1486 he comes to the town of Oberwesel, trailing a notary named Peter of Ingelheim who believes every word of the book to the letter, and there, at the Lower Gate, he finds Walburga — a midwife, a healer, a keeper of an herb garden and nine cats, and a woman whom the evening light refuses, for once, to cast as a witch. One night, watching from behind a rain-cask, Kramer sees Walburga’s cast-iron soup pot rise three inches off a hearth and hang in the air while she feeds her cats. It is the first genuine, impossible, harmless thing he has ever seen — and it undoes him.

What follows is a campaign run backwards. A papal legate, Von Spee, arrives demanding a fire, and Kramer — who has never once wanted to burn a woman — weaponizes the very contradictions of his own book to keep Walburga from it. A cup of chamomile tea cures a lifetime of heartburn. A twenty-pound cat falls asleep in the lap of the man who wrote that all cats are the Devil’s vehicle. In the moonlit garden, Kramer confesses the whole fraud, and Walburga corrects his prose.

Across one foggy night they load nine cats into six baskets and row for the far bank of the Rhine — Kramer, the Hammer of Witches, smuggling contraband felines over an international river. At dawn she offers him a life without the book, the fire, or the name: a small house, a garden, the cats. He cannot take it. He walks back to Speyer, to the second edition, to the centuries of fires — unable to pass a haystack without wondering whether a black cat is watching him.

Eighteen years later, in the winter of 1505, in the borrowed room at Kroměříž, a scratching comes at the door. An old, one-eared, black cat stands in the lamplight and lays a bundle of dried chamomile at the knees of the old man who refused the only true thing. Heinrich Kramer blows out his lamp, and, for the first time in eighteen years, lets the cat stay inside.