Justice Society of America #6

Synopsis

While Superman tells the JSA and JLA about the Legion of Super-Heroes, the Legion heads for Suicide Swamp to retrieve the last Legionnaire lost in the 21st century from one of the Secret Society's old headquarters. But a team of JSAers and JLAers has beaten the Legion there. The team finds Triplicate Girl, and just as everyone else arrives, the headquarters comes to life as Computo and kills one of Triplicate Girl's bodies. Superman realizes he has seen this before and that they are all fighting an illusion. But the Legionnaires have used this distraction to head off to complete their mission.