Booster Gold, Vol. 2 #4

52 Pick-Up, Part 4: He's Gonna Save Everyone Of Us
Rex has just finished repairing the Time Sphere after a collision with Barry Allen and Wally West, The Flash and Kid Flash, in the Timestream. No sooner than they're up and running, Rip gets a reading on Supernova's location... in Keystone City. Accompanied by the two Flashes, they zero in on his location, but are ambushed by Supernova, and Rex Hunter (also known as Jason Goldstein.) Rex was an old associate of Rip who once attempted to save the world by murdering Lex Luthor as a child, and for that Rip Hunter refused to work with him anymore. Now, outfitted with their own time sphere, the pair are apparently creating the situations that would have destroyed the universe.But Rip doesn't think Rex could have orchestrated all this by himself. Who's truly behind this attempt on the lives of the Justice League?
Release Date: 2007