Adventure Comics #319

Isolationist planet Throon builds a citadel to keep others away and uses a ray to disable all passing spaceships.

Characters: Ayla Ranzz, Bouncing Boy, Brainiac 5, Chameleon Boy, Chlorophyll Kid, Colossal Boy, Cosmic Boy, Element Lad, Fire Lad, Garth Ranzz, Invisible Kid, Jonathan Kent, Luornu Durgo, Martha Kent, Matter-Eater Lad, Mon-El, Night Girl, Phantom Girl, Polar Boy, Saturn Girl, Shrinking Violet, Stone Boy, Sun Boy, Superman, Thom Kallor, Ultra Boy