Lorenzo was a quiet Michigan town, known for its beautiful lake and resorts. Summer has arrived and water activities are abundant. It was one of the reasons Officer Royce Dashnaw took the job in the small town. Being a single dad, he wanted to live a quiet life where his daughter could enjoy the beauty of nature. Unfortunately, nature also has a dark side.

The peaceful serenity of Lorenzo has been disrupted by a series of strange events. A woman flees from the water with strange bites on her legs; bodies are found in the shallows, stripped to the bone; and the local population of fish have mysteriously disappeared.

As the body count rises, Royce learns the truth. Genetically enhanced fish have been dumped into the lake. With scissor-like jaws, they can reduce a full-grown adult to a mere skeleton in under a minute. A race against time ensues, as Royce and his partner struggle to evacuate the very large and busy lake before too many fall victim to the shredders.