Former Royal Navy diver Imogen Waide's job thrusts her into people's lives on their worst days. Called to Brandywine Lake in Kentucky to search for a missing child, she finds the idyllic resort town far from ordinary.

During a routine dive, she discovers a horde of discarded bones. Among the animal remains is a distinct human skull marred by a traumatic and bizarre injury.

Maxwell Rue, a native hunter and conservationist, aids in the rescue efforts. Rue has lived in the Appalachian Mountains his entire life, trapping and relocating dangerous animals. His inability to identify the markings is an ominous sign.

During a torrential storm, a second child goes missing.

Waide and Rue are on the hunt for a creature moving unseen in Brandywine Lake. Will they find the lost children, or will the beast add two more skeletons to its collection?