Larry Griffin plots to get even with former fellow grad student Joan Brockton, who was partly responsible for his expulsion from a freshwater research institute in northern Michigan for sexual harassment. Griffin, now a student at a Caribbean medical school, creates transgenic freshwater jellyfish with fatally toxic stinger genes from the marine box jelly and introduces them into a lake near Traverse City, causing fatalities and general panic. Griffin plants incriminating evidence in Joan Brockton's lab that falsely implicates her as the perpetrator. Brockton's partner, postdoctoral scientist Paul Tyson, struggles to reveal Griffin's treachery and bring him to justice.