Superman’s old enemy Grax plants 12 bombs on Earth. Starring Aquaman, Batman, Robin, Superman, Wonder Woman, Wendy, Marvin, Wonder Dog, the Wonder Twins and Gleek (making their first comic book appearance), Hawkman, the Flash, and Green Arrow.
The Wonder Twins come to Earth with a message of Doom for the Planet. The Interstellar villain Grax planted bombs to destroy Earth. The first 4 were to destroy Earth's cultural history, but Justice League members Hawkman, Flash, Elongated Man along with the Global Guardians diffused the bombs.
At the end of the issue Grax has planted 5 more bombs intent to wipe the minds of the Earth's populace within 26 minutes. At JLA Satellite HQ, Marvin sends Batman and Robin, Black Canary, The Atom and Red Torndado to deal with these bombs.