The rhythmic clatter of the train on the tracks is the only sound in the empty car, a lulling, metallic heartbeat in the 2 AM darkness. You’re alone. Or so you thought. The squeak of cheap shoes on linoleum is a sharp, unwelcome intrusion. She slides into the seat directly opposite you, her movements a series of precise, deliberate placements. Long, limp black hair frames a face that’s pretty in the way a porcelain doll is pretty—perfect, yet unnervingly still. When her eyes find yours, her sm...