Legion of Super-Heroes co-founder Cosmic Boy and his girlfriend Night Girl return from a journey to 20th-century Earth, where they are attacked by the Time Trapper and discover that he has altered history, erasing Superboy from existence.
A decade later, Brainiac 5, Sun Boy, Blok, and Invisible Kid arrive in Smallville, attracting the attention of Superman.
From his Citadel, the Time Trapper observes the transpiring events and recalls that he created a "pocket universe" (with a different Earth, a different Krypton and a different Kal-El) to which he has continually directed the Legion during all of their journeys to the 20th century.
Superboy and the Legion depart to rescue the other Legionnaires and face the Time Trapper, leaving Superman behind to preserve the timeline.
Superboy explains to the Legionnaires that the Time Trapper protected his Earth during the Crisis in return for his help in defeating the Legion.
Following Superboy's disappearance from the pocket universe Earth, its Lex Luthor is tricked into releasing General Zod, Quex-Ul, and Zaora from the Phantom Zone.
In the 1990s, Keith Giffen, Tom and Mary Bierbaum, and Al Gordon revised the Legion's history, replacing the Time Trapper with his former underling Glorith and having her banish Valor to the Phantom Zone.
[24][25] This storyline's issues should be read in the following order: This story is included as part of the trade paperback collection Superman: The Man of Steel, Vol.