The job listing is too good to be true. Live-in caretaker for an elderly woman. Private room. Meals included. $800 a week. Light duties. The only catch: three previous caretakers quit within a month.

Claire, a nursing student desperate to escape a moldy apartment and a deadbeat roommate, signs the contract without asking too many questions.

Mrs. Hartwell is ninety-one, frail, mind wandering. She calls Claire by the wrong names, carries on conversations with people who aren't there, and issues one warning with absolute clarity: Don't go in the basement. Don't open that door. Not for any reason. Not even if you hear them crying.

The crying starts on the fifth night.

Claire finds books hidden throughout the house. Old books about faeries and changelings. Academic texts about children who aren't quite right, who don't eat human food, who sing songs in languages no human has ever spoken. She finds photographs of the children who passed through Mrs. Hartwell's "foster home" over the decades—and some of them look wrong in ways the camera shouldn't be able to capture.

When Mrs. Hartwell dies, Claire finally opens the basement door. The space is larger than the house above it. Iron cages line the walls. And the children inside are hungry.

They've been hungry for a very long time.