Justice League Vs. The Legion of Super-Heroes

"One thousand years in the future, a Legion of Super-Heroes comes together to dedicate their lives to recapturing the great age of heroes of the 21st century. When the heroes discover that reality is falling to a great darkness in both times simultaneously, the Justice League and the Legion of Super-Heroes must team up to stop it all. Soon, the Justice League are trapped in the 31st century, and the looming terror of the Great Darkness hovers over both time periods simultaneously. Even as the great heroes of the 21st century get to experience the fantastic far-flung future, the mysteries behind the Gold Lantern and the Great Darkness threaten all of existence"--Publisher marketing.