Fantastic Four #115 Oct 1971
"The Secret of the Eternals"
After being contacted by the witch
Agatha Harkness, the Watcher has agreed
to explain to the Fantastic Four the origins of the being known as
the Over-Mind.
He shows them a distant galaxy where centuries ago existed the planet
Eternus,
home of the Eternals, a warrior race who had mastered science and conquered death.
They went out into the stars, enslaving every world they came in contact with.
Having subjugated the known universe, the Eternals then began amusing themselves
by pitting their alien slaves against their greatest warriors in arena combat.
One of their greatest warriors was a man named
Grom who
won the title of Champion of Champions among the Eternals.
However, the Eternals soon became aware of the massive planet of
Gigantus, a world that dwarfed galaxies.
The Gigantians soon became aware that the Eternals sought
to conquer their world and prepared to oppose their attackers.
The Eternals found that the task of conquering Gigantus was difficult due to the massive size of that world.
Ultimately, they decided to destroy the entire world instead of enslaving it.
As Gigantus was destroyed by massive bombs, some survivors managed to escape the death of their home world.
The Watcher explained that the ruins of Gigantus spread across the known universe and eventually formed
into new worlds and stars. The last survivors of Gigantus then flew their ships to Eternus and attacked.
As their world crumbled around them, the greatly diminished Eternals all transferred their minds into one being -- Grom.
Reborn into the Over-Mind, the rulers of Eternus placed him in a state of suspended animation and launched him into space.
There the Over-Mind slumbered for centuries until the faithful day that
he would awaken and strike at the universe in revenge for his people.
Finishing his tale, the Watcher tells the Fantastic Four that is all
he can tell and that he can offer no aid before teleporting away.
Plot by Stan Lee.
Script by Archie Goodwin.
Pencils by John Buscema.
Inks by Joe Sinnott.