A lightning storm causes a nest of giant ant eggs to hatch. The giant ants cause havoc and destruction and Zandor and the Herculoids must put an end to them. A hideous monster emerges from a swamp and goes on a rampage, destroying anything it comes in contact with by its radioactive touch. It eventually traps Dorno and Gleep in a cave, and it is up to Zandor and the rest of the Herculoids to rescue them and defeat the creature.