Old Friends

After passing through the time-portal the Green Lanterns were shocked to find themselves outflanked by both the Zamarons and Lex Luthor's Legion. Jordan Cross had hoped that he would find the Justice League there, but they were nowhere to be found.

Earlier that day, the day the time-portals opened, Chloe Sullivan and Kyle Tippet finally emerged from their chambers in the Fortress of Solitude, where they had been kept by Jor-El in stasis after being critically injured. When they emerged Jor-El gave them all of
Clark's powers as he had promised years before.

They joined the Justice League, who was fighting the rearguard of Lex's Legion. The rearguard was defending a weapon built by Lex that would allow him to easily destroy the Green Lanterns in orbit.

With help from Kyle and Chloe the Justice League easily defeated the Rearguard, destroyed Lex's weapon, and made their way to the time-portals, where they would join the Green Lanterns in a battle against the vanguard of Lex's Legion.

Bruce Wayne (AKA Batman) and Diana Prince (AKA Wonder Woman), members of the Justice League, had recently been married. After decades of fighting crime they were looking forward to finally settling down. After Chloe and Kyle came to the League's aid Bruce asked Diana to stay behind, fearing that she would not survive.

Diana reminded Bruce of the time when they were younger, twenty-nine years before, when they first joined the Justice League. A few years earlier, the council leader of the Justice League was Jordan Cross.
Jordan's example inspired Diana to rebel against her controlling mother, leaving her peaceful, secluded island and venturing into the darkness of the 20th century, in pursuit of justice. If Diana walked away and Jordan died she wouldn't have been able to forgive herself. She was willing to risk her life to save Jordan, even if it only gave her the opportunity to speak to him once.

Bruce was furious. He told Diana that he wouldn't go with her and left.

Later, Bruce changed his mind and followed her, secretly watching over her during the battle.