When a young couple – Anne and Harold – moves into a new home without knowing it was a site of horrific murders, Anne's loneliness and strange behavior makes their relationship complicated, especially after Anne meets 'Mary', a dark presence from which she can't escape.

Meredith Hendricks happens to be the best cop in her quiet town on Lake Tahoe. When a black-market exotic species dealer named Clint is paroled from prison, something he let loose begins to make its presence known. Swimmers and land-lovers alike begin to become part of the food chain at an unbelievable rate. Meredith and her team discover that they're not just hunting one eating machine, but a whole family of them. Not everyone will make it out alive, but those who do will never forget this summer at Shark Lake.