In pursuit of the time-traveling criminal known as Universo, the super-powered kids from the 30th century travel back to the 1960s to enlist the aid of the "greatest teen superhero ever" - Robin, the Boy Wonder! But Batman's hard-boiled nemesis Egghead has stolen one of their unattended time bubbles and taken off to the Legion's own time period. Looks like Batman has to head to the far-flung future with one group of heroes while Robin stays in the swinging sixties with another. Holy time-travel paradox!