After the Avengers defeated the Masters of Evil and the Fantastic Four triumphed over Doctor Doom, a new, unexpected, and far more dangerous crisis forces the two teams to unite to save the world, all of reality, and the timeline.
Strange temporal anomalies begin to occur around the planet, with the emergence of impossible technologies, armies, and creatures from the past and future. The world descends into chaos.
The Fantastic Four begin to investigate these disturbances, leading them to Egypt, where a pyramid-shaped ship materializes, forcing the team to confront Rama-Tut, a mysterious pharaoh and time traveler with technology advanced even for the 21st century. At the same time, the Avengers in France confront the Scarlet Centurion, a masked conqueror from the future who emerges imposing military dominance over European countries. Both believe that the present should be shaped by their visions of absolute order.
As if that weren't enough, the real threat is yet to come: Kang the Conqueror, a time traveler who dominates his era centuries in the future, is coming to dominate the present, since the 21st century, the age of heroes, is a central axis in the timeline, and whoever controls it holds the future of humanity in their hands.
That's when the great revelation is made: the three figures are actually the same being from long periods of different time.
To stop Kang, the Avengers and the Fantastic Four unite, taking the fight to Kang's time, knowing that if they fail, everything they have fought for will have been in vain.
They operate on several fronts, with Steve leading both groups, Reed, Tony, and Hank being the brains, Johnny and Thor the firepower, Susan and Jan the reason and emotion, while Ben and Hulk are the brute force.
