Adventure Comics (1938) 319-A

Tales of the Legion of Super-Heroes in "The Legion's Suicide Squad" and "The Charge of the Substitute Heroes!"
*The mysterious jungle planetoid, Throon, is inhabited by beings who reside, unseen, inside a single colossal citadel. When ships passing by in space are disabled by rays projected from that world, followed by an announcement that its people will destroy all ships coming within 30 million miles of it, the Science Police Chief and the President of Earth call upon the Legion to destroy the ray-projectors, lest all space-traffic be stopped. Using a device called a planetary chance-machine, seven Legionnaires: Brainiac 5, Saturn Girl, Bouncing Boy, Superboy, Lightning Lad, Chameleon Boy, and Invisible Kid, are chosen for the task.

Upon arriving on Throon, however, all are defeated by the terrible weaponry in the citadel. The Legion then selects five more members: Star Boy, Cosmic Boy, Ultra Boy, Triplicate Girl, and Matter-Eater Lad, to rescue their comrades. They also fall in defeat, and the remaining Legionnaires, Mon-El, Element Lad, Phantom Girl, Colossal Boy, Light Lass, Sun Boy, and Shrinking Violet go to Throon, only to meet the same fate as the others.

All of this has secretly been watched on monitors by the Legion of Substitute Heroes. They go to Throon themselves, and while Polar Boy, Chlorophyll Kid, Fire Lad, and Stone Boy launch a suicide attack on the citadel, Night Girl infiltrates the building. After searching through its many empty rooms and halls, she finally finds two old men, the last survivors of their race, who had wanted to protect themselves from possible conquest.

After destroying their weaponry but otherwise leaving them in peace, the two Legions, now fully recovered, return to Earth. The Substitute Heroes are given a triumphal welcoming parade in Metropolis for their daring rescue, with the Legionnaires themselves standing on the sidelines and cheering. *Source: The Official Legion of Super-Heroes Index #2 - Published by ICG.

Superboy in "Superboy's Best Friend"
Reprinted from Superboy (Vol 1) #77.
Superboy tells his new best friend Freddy Shaw, about his secret identity as Clark Kent. Freddy then tells everyone, including his ex-convict half brother Joe. Freddy is on his death bed and everyone believes his stories are caused by his brain fever delirium.