Return of the Hero, part 1 of 3. A Zero Hour crossover issue. The time is over a decade ago, before the formation of the Justice League of America. An alien race called the Plasma Men have come to invade Earth, and the heroes of Earth have gathered together to fight them. Superman, Flash, Green Lantern, Aquaman, Black Canary, and Martian Manhunter have all come together at the request of the hero Triumph, who is coordinating the heroes against the Plasma Men. While Triumph, Superman, and Martian Manhunter stop their plans in the Earth’s core, Aquaman and Flash try to communicate with their organic ship in orbit. Triumph sacrifices himself to save the world, but finds himself trapped in time where no one remembers him. With Zero Hour, Triumph has returned to a world that no longer remembers his existence.