Dinosaurs suddenly appear in Midway City, and cavemen rob a bank before being stopped by Hawkman and Hawkgirl. One wounded pterodactyl doesn’t vanish with the rest and, before dying, reveals they were brought from 1,000,000 B.C. by someone from the present. Following a radiation trail, the heroes find Dr. Malevolo’s lab at a closed carnival. He sends Hawkman back in time, where he loses parts of his memory and becomes a hero to local cavemen. When Malevolo accidentally recalls everyone to the present, he commands Hawkman to eliminate Hawkgirl. Shayera restores Katar’s memory, and together they defeat Malevolo and destroy his time machine.
