The Maddening Menace Of The Super-Beast! While traveling through the citadel of the High Evolutionary, Thor and Jane Foster are attacked by the hyper-evolved wolf known as the Man-Beast. Consumed with evil, the Man-Beast attacks Thor and, surprisingly, is a match for the Thunder God. The High Evolutionary and his Ani-Men arrive shortly after the Evolutionary using a high-tech dog-whistle device to cause the Man-Beast pain. The Man-Beast flees the scene, and Thor attempts to stop it by throwing his hammer, but the Man-Beasts mental powers deflect it.
The Man-Beast flees into the High Evolutionary's genetic laboratory. When Thor goes after the creature, the Evolutionary stops him just in time to prevent him from crashing into the Anti-Matter Barrier erected around the lab that would surely have destroyed the Thunder God. The High Evolutionary fears that the Man-Beast may find his Evolution Ray and use it to create more creatures like itself.
Meanwhile, back in Asgard, Odin watches is lost in thought as he is supposed to pay attention to a trail of combat between Balder and another warrior. When Balder wins the fight, Odin commands Balder to go and seek out Thor so that the Thunder God might help with a premonition of some new danger that threatens the Golden Realm.
While back at Wundagore Mountain, Jane finds a safe place to hide while the High Evolutionary, Thor, and the Ani-Men draw out the Man-Beast for a full-out assault. Even with the combined might of all these mighty warriors, they are still no match for the Man-Beast's superior powers and an army of his own highly evolved creatures. The Man-Beast fights them aside except for Thor, who continues his assault. When the two are locked in a grapple, the Man-Beast tries to use his superior mental powers against Thor. However, this gives Thor the physical advantage, and he beats the Man-Beast into submission. The Knights of Wundagore then fight off the Man-Beast's evil Ani-Men, and they are all loaded up in a Star Chamber and launched into the Dromisana galaxy.
With the battle over, the High Evolutionary removes his mask, revealing him to be a normal human being. He explains that he began inventing high-tech devices that would speed up animal evolution, his first experiment being his pet dalmatian which was accidentally shot and killed by a hunter. Deciding to work in seclusion, the Evolutionary would build his base in Wundagore Mountain and create his Ani-Men. However, he believes he and his new creations need to be away from the taint of mankind, and so he bids Thor and Jane farewell.
As Thor and Jane leave the Evolutionary's citadel, it suddenly transforms into a rocket. It launches into the sky, the beginning of a new destiny for the High Evolutionary and his creations.