In the small town of Dundas, Indiana, genetic researcher Ken Horvath (MICHAEL SHANKS) is working in his laboratory at night. He moves over to a glass case holding eight very large yellow jacket wasps. He sprays the yellow jackets with a greenish solution and sets his timer. The wasps die in record time.

Later that night, we see the same dead yellow jackets. There is a stirring - a limb twitches, a body moves. Two of them are still alive and escape from the glass case! The halls are quiet, dark and empty - all the workers have gone home.except for one. Roy Peltor, the night janitor, hears the buzzing sound getting closer and closer. The two yellow jackets dive at his face. Roy screams in fear and pain, striking out blindly, crushing one of the wasps, but his face is bleeding as he falls to the ground, dead, and the surviving wasp flies away.

Something big is happening in the town of Dundas. For the first time ever, its annual Barbecue Cook-Off will be televised by Gourmet TV, bringing much needed business and publicity. Phineas Washburn (TIM THOMERSON), the owner of the company that sponsors the TV broadcast, arrives with the television crews, as the mayor and officials promise that the event will go exactly as planned.

Roy's body is taken to the morgue so the coroner can perform an autopsy. The coroner hears it - a strange buzzing sound coming from inside Roy's mouth. He opens Roy's jaw and a wasp flies out attacking him, stinging repeatedly.

Now there are two deaths, and Christina (CAROL ALT), an entomologist from the University, suspects that something is horribly wrong as she takes blood samples from both the janitor and the coroner. Christina knows that something is very unusual about these wasps, and when she learns that the first death occurred at Ken's lab, she sets out to find him. Ken and Christina realize that the experimental pesticide causes a mutation in the wasps and they desperately need to find the single remaining wasp.

Meanwhile, a father cooking burgers for his family's dinner is attacked by a nest of hungry wasps. He calls Q, the town exterminator, who knocks the nest into a canvas bag. Then Q sprays into the bag the new experimental pesticide that he "borrowed" from his friend Ken Horvath. Just to be thorough, Q crushes the wasp nest. A swarm of the now MUTATED wasps pours from the nest and flies away, leaving Q for dead.

When Ken and Christina learn what Q has done, they know there will be mass death and devastation if the swarm is not stopped. The wasps are getting much more aggressive, and their venom is growing in strength. Now the swarm is not just attracted by meat on the barbecue, but also by LIVE meat.human beings. The authorities turn a blind eye, hoping that their televised event will go off according to plan. The whole town will be at the big, televised event, each man, woman, and child a potential victim of the swarm. Pesticides will not kill these wasps, and no one will listen, as the swarm gets closer and closer to the town square. The clock is ticking and Ken and Christina have to find a way to stop the swarm before their town is obliterated.