Connor and Otis, honor students at Pendrake Middle School, stumble into trouble while fishing from their old skiff on Peabody Pond. They attempt to aid Dr. Lambert, a geneticist, who crashed his car on a forest trail while fleeing his pursuers. During the doctor's violent abduction, a vial of an experimental hormone rolls down the hillside and shatters on the shore, unleashing horrific changes in the simple aquatic life. Situations deteriorate as the boys struggle to stay one step ahead of the thugs while waging battle with the monstrous mutants of Peabody Pond. They vow to solve the crime on their own, but piling secrets upon lies, they enlist some unlikely allies and open the doors to a summer vacation fraught with mischief, mystery, mayhem, and death - as well as far more adventure than either boy could have imagined.