It’s 1995. Fresh off the bus from New York City, a broken-hearted 35-year-old named Anna Pigeon takes her first job as a park employee: a decidedly unglamorous, seasonal stint at the Glen Canyon National Recreational Area. On her day off, she goes hiking alone in the park—never to return.

Her co-workers assume she’s moved on since her cabin is cleaned out. But when Anna wakes up—trapped at the bottom of a well, naked, with no supplies and no memory of how she got there—she must draw upon all of her strength, courage, and skill to survive.

Because whoever set Anna’s trap isn’t through with her yet…