It's the 100th meeting of the Justice League of America! But the celebrations are cut short when the JSA of Earth-Two send out a call for help! Both teams must find and recruit the members of the only group of heroes capable of standing against the new threat: the Seven Soldiers of Victory!
Carthan, banished from his home world Dryanna to Earth by his ruler Xandor, attempts to contact the Justice League for help but cannot do so directly; he activates three machines of destruction that hold him to Earth and takes Green Arrow hostage, hoping that the Justice League can deactivate the machines and free him.
In attempting to escape prison, Felix Faust accidentally creates a mystical duplicate; The JLA must determine which is the duplicate Felix Faust before his eventual disappearance causes the end of the universe; but Snapper knows that both are mystical duplicates and the original Felix Faust remains in jail, so the duplicates are brought to the real Faust and eliminated.
Having found an ancient book that appears to indicate that he once defeated the JLA, Xotar travels from 11,960 to the present to test four weapons against the Justice League in order to determine which weapon will help him defeat the Intersolar Police of his own day. But the JLA counters each of Xotar's weapons and returns him to face justice in his own time. Secret of the Sinister Sorcerers!