The story begins as a young alien woman named Dusk arrives on Earth to warn the population that a giant extraterrestrial being, known as the Sun-Eater, is heading our way. Dusk is a member of an unknown alien race, and does not speak or understand a word of English, so Saturn Girl uses her telepathic powers to translate for her. Dusk has attempted to warn hundreds of worlds, prior to Earth, about the Sun-Eater. Each planet had tried, in its own way, to stop the Sun-Eater, but every attempt was as unsuccessful as the last one. This has convinced Dusk that the Sun-Eater is indestructible.
Despite her warnings, the Justice League still try to stop the Sun-Eater.