Adventure Comics #363

Adventure Comics #363 (On Sale: October 31, 1967) features another Curt Swan and George Klein cover.

"Black Day for the Legion" is by Jim Shooter and Pete Costanza and continues from the previous issue. Fighting back, the Legionnaires defeat Morlo's Chemoids and capture the villain, while Superboy destroys the smog-maker. However, Morlo breaks free and leaps off the platform into a dense forest below, where Superboy's X-ray vision fails to spot him.

Meanwhile, Mon-El's party, including Element Lad, Sun Boy, Saturn Girl, Colossal Boy, and Lightning Lad, approaches Daxam, and is greeted by a deadly rain of alkali hailstones and ball lightning. Similar chemical storms have razed all major cities there, and the Legion learns that Mantis Morlo, operating from an undersea base in the Sea of Ornal, is responsible. The heroes penetrate his base and destroy all his weaponry, but the villain escapes in a submarine.

At the same time, Dream Girl and her comrades, Star Boy, Invisible Kid, Ultra Boy, Matter-Eater Lad, Chameleon Boy, and Phantom Girl, greet the High Assembly of her world, Naltor. They inform the Legionnaires that artificially induced food contaminates have given the populace bad dreams, and have thrown them into a panic. Ultra Boy flies into space, where he uses his penetra-vision to "peel" Naltor, layer by layer, until he finally finds the base of Mantis Morlo at its very core. The Legion rushes to capture him, but he succeeds in escaping. Chameleon Boy, whose antennae tingled when he stood near Morlo, stops the others from pursuing him.

During all of this, the real Dr. Morlo is safely ensconced in his orbital laboratory. He gloats over his victories, having used Chemoid doubles of himself to create disasters to lure the Legion to some of their home worlds. His real target is Earth, and he paints a target on the globe, then launches a bomb to burn the planet to a cinder. Reprinted in Legion of Super-Heroes Archives Vol. 7 HC.

Edited by Mort Weisinger.