(1st Appearance of the Legion of Super-Villains; 1st Appearances of Cosmic King, Saturn Queen, and Lightning Lord).
"The Legion of Super-Villains" - - *Lex Luthor, who has known of the existence of the Legion of Super-Heroes for years, theorizes that there should also be a Legion of Super-Villains, and, working from prison, he constructs a device that allows him to contact them. The Super-Villains break him out of jail, and, with him, lure Superman to a remote planetoid and capture him.
However, before these criminals can execute Superman, the adult Legion of Super-Heroes intervenes, and fights the Super-Villains to a standstill. Unable to defeat them, the Legionnaires listen as Luthor challenges them to sacrifice one of their number for Superman. Saturn Woman volunteers, and the villains allow the Man of Steel time to perform one last deed in her honor. With a giant shovel, he gathers some material from the rings of Saturn, and creates a similar ring around the planetoid. When he does, Saturn Queen surprises everyone by suddenly using her powers to defeat her partners.
Superman then explains that he had theorized that radiations from the rings of Saturn would cancel out the evil tendencies of inhabitants of that world. He gives the reformed Saturn Queen a small chunk from the rings that will prevent her from returning to evil, then takes Luthor back to his prison on Earth as the Legionnaires likewise take the Super-Villains to jail. *Source: The Official Legion of Super-Heroes Index #1 - Published by ICG.
Also features the back-up stories: "The Great Mento" and "Krypto Battles Titano".