An alien space vessel crash-lands on Earth just off the West River in Metropolis. A woman named Dusk emerges only to find Superman and the Legion of Super-Heroes standing before her. Saturn Girl uses her telepathy to translate the frightened woman’s thoughts. Dusk warns them that an entity known as a Sun-Eater is en route to this star system. When it arrives, it will consume all of the energy from the sun, thus destroying all life on the planet Earth.
Superman calls together a special convention of superheroes. Attending are members of the JLA (past and present), the Legion, the Marvel Family and many others. Mister Miracle decides to create an over-sized Boom Tube to funnel the Sun-Eater to an unoccupied domain. The Sun-Eater overloads the Boom Tube and the plan fails.
The next strategy involves the creation of a secondary sun to act as a lure for the Sun-Eater. All of the energy-based heroes pour their powers into the creation of a new sun, but this too proves to be a fruitless endeavor.
Elsewhere, Lex Luthor decides that it is time to step up and lend a hand.