Morgan Hubbard was kicked out of MIT for conducting illegal experiments in order to discover an alternative to pesticides. Her idea was a roach that would devour other roaches, and then die off after one generation. She approaches the mayor of a New England town, who allows her to secretly pick up where she left off in this community in exchange for a "guaranteed" prosperity. What starts out as a wide infestation of roaches in the area soon balloons into the insects devouring animals and shortly after, people.
Throughout all this, Hubbard shows no emotion for what is happening, and even captures a stray cat so that she can watch it be eaten alive by the roaches before her very eyes. The town sheriff, Elias, the local exterminator, Homer, and the mayor's daughter, Elizabeth, all band together to find a way to defeat the insects after nearly all of the town's residents have been killed. Hubbard, however, obstructs their efforts through lies and sabotage in order to further pursue her own interests. When she and Elizabeth finally arrive at a cave where the roach nest is located, Hubbard immediately begins taking samples in a petri dish for future use. However, while doing so, the queen roach - bipedal, and larger than that of an adult human - appears behind her. The queen then tears off Hubbard's right arm and then kills her by biting her skull in half.