Rarely does a vampire encounter story manage to be this quietly unsettling without ever saying the terrifying thing out loud. Nora, a struggling actress in 1980s New York City, takes a live-in caretaker’s job with a man named Casimir van der Broek in his Upper East Side brownstone, and what she finds there will stay with you long after you finish listening.

The clues accumulate slowly. A fifteenth-century Latin book about vampires. A portrait authenticated to the seventeenth century, bearing a Dutch frame stamp from 1698. A man who never eats, never sleeps at night, and never steps into daylight. (Casimir’s formal courtesy somehow makes everything more disturbing, not less.) The evidence piles up, piece by piece, each detail adding to the same unthinkable conclusion.

Have you ever taken a job or entered a building where the atmosphere ...