A mysterious plague has eradicated many of the world's women, and those that survived are now heavily regulated, either sold, kept or exploited for various purposes. Katie is a teenager who is being prepped for reproduction. But just as she's earmarked to start the ominous program, she manages to escape the government-run facility, running out into the Shetland Isles.

On their way to a family get-together, the Herring family are in a bad car accident, waking in a terrifying, dark basement. Something is there with them. Caged. And it craves human flesh. With a mysterious overseer aiding the creature like a pet, the family must work together to find a way to defeat them both and make their escape.