Adventure Comics #354

In "The Adult Legion!", the Legion of Super-Heroes faces a shocking twist when they uncover that the saboteur behind their latest crisis is Ferro Lad's long-lost twin brother—under the mind control of the Legion of Super-Villains. Written by Jim Shooter and illustrated by Shooter and Curt Swan, with inks by George Klein and letters by Milton Snapinn, this 1967 adventure blends mystery and future intrigue, all brought to life with Curt Swan’s dynamic cover art and George Klein’s precise inks.