The film opens with newspaper photojournalist Audrey Aimes accidentally stumbling upon a small town (Ludlow, Illinois) which has been inexplicably destroyed. All 150 residents are missing, and the evidence indicates they are dead. Incredibly, the local fields are also barren, as if a swarm of locusts had eaten all the crops. Aimes suspects that the military is covering something up, and travels to a nearby United States Department of Agriculture experimental farm to learn what creature might have caused the agricultural destruction. She meets Dr. Ed Wainwright, who is experimenting with radiation as a means of growing gigantic fruits and vegetables to end world hunger. Wainwright reports that there have been a number of mysterious incidents nearby, and that locusts have eaten all the radioactive wheat stored in a nearby grain silo.