The Legion travels back in time to Krypton on the day of its destruction in order to save the citizens of 30th Century Tokyo.

Superboy travels back into the past, in his own rightful time, to live as Clark Kent. He puts his glasses down on a shelf with an alien replaces them with another set of glasses before disappearing. Clark uses his eye beams and destroys the lens of the glasses, stepping on them before his alter-ego could be found out. He realizes, though, that those glasses aren't his since his original glasses are Kryptonian and don't melt with his eye beams. Just then the Legion of Super-Heroes arrives for Superboy's help as something weird is going on in the future and it seems the ordeal with the spectacles is only the beginning of this weird adventure!