The Brave and the Bold 29 (Facsimile Edition) #1

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.