Booster Gold #23

Raven arrives at Steve Dayton's mansion to find all of the Teen Titans dead. As Booster explains the situation, Rip arrives, and the three, along with Skeets, travel to 2020 where the death of the Titans led to Trigon destroying the JLA and conquering the Earth. The heroes encounter Zatanna and Kyle Rayner (who in this timeline never became a Green Lantern) who lead an underground movement against Trigon. But the time travelers' presence has been detected, so Booster allows himself to be taken away by Trigon's sentries to protect the underground, and is dropped at the feet of Trigon himself.