Synopsis
An asteroid makes its way suspiciously neatly into an orbit around Earth, and the antenna sticking out of 1 end confirms it's no ordinary rock. Inside is the complex home/laboratory of the High Evolutionary. He has returned home after months in space with a new plan, Project Alpha, and he's recording a history of what led up to it.
He covers his method of extremely rapidly evolving animals into intelligent humanoids, his New Men on Mount Wundagore as seen in Thor #134-135. But when he evolved a wolf something went wrong, creating the evil Man-Beast who then created more evil New Men. With Thor's help High Evolutionary exiled them to the Dromisana galaxy.
After that he took his good Knights Of Wundagore to a planet Wundagore II in another solar system. But they reverted to their bestial natures and turned on him. He kidnapped Hulk and brought him to Wundagore II in Tales To Astonish #94-96 to help. But it was too late so Herbert Wyndham evolved himself into a godlike immortal. As he left for a higher plane he devolved his New Men back to animals and sent Hulk back to Earth.
Now we learn that loneliness made him return to his armoured mortal form and create a new version of his only faithful Knight, Sir Ram. (Wyndham says here he brought Sir Ram back from death (TTA#95) but the various authorities say this is the 2nd of several Sir Ram's.)
Now in orbit they note a cocoon floating in space nearby. They bring it aboard before moving the 'asteroid' to the far side of the Sun. Evolutionary puts Project Alpha temporarily on hold while he investigates this new enigma. Probing inside the cocoon he detects a golden man-god like the ultimate human he had hoped to create with his earlier experiments who would have been his son. And the being speaks to him telepathically.
He says he is not born of man or woman and has no name, but men have called him Him. He relates how he was created by evil scientists on Earth in Fantastic Four #66-67, but when he emerged from his cocoon he killed them and left for space. Fate (or the Watcher) caused him to return to his cocoon which was brought back to Earth where he emerged again in Thor #165-166. There he sought a mate in the Asgardian goddess Sif but was opposed by Thor. So he cocooned himself again and left for space once more where he metamorphosed within the cocoon.
From within the cocoon Him becomes interested in Wyndham's Project Alpha. The Evolutionary has a chunk of Earth rock (from the core?) from which he is going to grow a new Earth hidden on the opposite side of the Sun from the old Earth. This Counter-Earth too will evolve human beings but they will be without aggression, so this Earth will be a paradise.
He places the rock in orbit and increases its gravity so it quickly attracts other space rocks to create a molten globe. Wyndham causes a molten mass to separate off to form a Counter-Moon companion. And somehow he accelerates the process so that the Earth rapidly cools and develops land and seas, and then life evolves until it includes man-apes. Now the Evolutionary slows the process for the critical stage. But the strain on him is too much and Herbert Wyndham falls asleep as true men emerge.
Secretly watching from a cloaked spaceship is the Man-Beast returned from the Dromisana galaxy with his evil New Men. They enter the asteroid and kill Sir Ram (again). Man-Beast gains revenge on his creator by urging a Counter-Earth human to kill a fellow with a handy tree branch. Thus is murder introduced into paradise. The Beast now speeds time up again and history repeats itself up to the present day.
Herbert Wyndham wakes too late to undue the damage - he can only attack the Man-Beast and mentally blast the New Men. But Man-Beast mind-blasts him too, and they seem equally matched as Him observes from his cocoon until the New Men revive and dog-pile on the Evolutionary. Then he breaks open the cocoon to help Wyndham. And Man-Beast and New Men vanish.
(Note that the golden being's main metamorphosis seems to be swapping his briefs for the costume on the cover.)
HE tells Him what Man-Beast mentally told him as he left. He and the New Men have gone down to Counter-Earth to further corrupt it. Evolutionary is about to destroy his creation to save it but Him stays his hand. As he watched Earth history unfold he saw much goodness in humans as well as evil. He offers to go down to oppose the Man-Beast. Wyndham accepts the offer even though it means sacrificing the man who might have shared his life as a 'son'.
But before Him goes HE places a glowing green gem on his brow which he says will help Him. And as he descends to the world below it is implied that the immortal golden god becomes a mortal man. Evolutionary predicts that men will see Him's unearthly powers and call him Adam Warlock. And his crash-landing on Counter-Earth is witnessed by a group of teenagers.