In New York City, the Juggernaut is seen standing over the remains of the Mighty Avengers. Iron Man’s helmet is laying separate from the rest of the armor, Thor’s decaying hand rests over Mjolnir and even Captain America’s shield is cracked. They’re all dead. Just like the rest of the world.
Juggernaut turns around to see three partially-damaged Sentinels standing above him for termination. On one hand, he’s angry due to what they’ve done to the world. On the other hand, he’s a bit happy since he hasn’t seen one of these bots in months. He has fun with the robots and succeeds in killing one. As he grabs a second one, the Sentinel announces the odds of surviving this fight with the Juggernaut as 0.000463%. Juggernaut proves those odds by smashing it to bits. The third tries to fly off for survival, but Juggernaut jumps onto its leg.
He beams in pride, but inside, he feels a bit empty. If those are the last ones, then he’s truly alone. He continues to wander and soon comes across Xavier’s mansion. He wanders around and sees what’s left of the Danger Room. Among the wreckage, we see Cyclops’ cracked visor in the rubble. Juggernaut decides he can’t face these demons and leaves. As time passes, all he can do is wander and occasionally run through buildings. There are no people, animals or even Sentinels left to interact with. He wants so desperately to die, but his own invulnerability won’t let that happen.
Years pass and Juggernaut has yet to age. He comes to the Grand Canyon, which is where the Sentinel’s factory used to be before he destroyed them all. He now wonders if he should have let them be. Perhaps if there were enough created, they could have killed him and ended his misery. Wandering through, he encounters Magneto.
Magneto attacks Juggernaut unprovoked, which angers him. Magneto explains that during the creation of the Sentinels, he was on the Stranger’s planet. He viewed what was happening on Earth and tried to escape to it in time to save everyone. But he was too late and he holds Juggernaut responsible. During this talk, Juggernaut breaks through the defenses and Magneto gets weaker by the moment.
When the Sentinels first appeared, they attacked the Avengers and Fantastic Four by surprise and killed both teams. Then they turned against their creators and changed their programming. In order to kill all mutants, they converted their power cells into a toxic radiation that kills all humans and mutants. The Juggernaut, protected by the enchantment of Cyttorak, is immune. But none of this would have happened if the X-Men were there to stop the Sentinels before they could run amock. Another toy Magneto got to use from the Stranger was a viewer that allowed him to look into alternate realities. Every reality that had the X-Men survive their encounter with the Juggernaut didn’t suffer this cataclysm.
Magneto collapses and dies before Juggernaut, telling him that his own petty jealousy is what’s to blame for all of this. Juggernaut screams in anguish and goes on a rampage. He ends up falling through the floor and goes down a couple levels to a sub-basement. He’s surprised to find ice nearby. Above him is Iceman, with ice covering him and his own voice stuttering from his inability to control his powers. Ever since Juggernaut murdered the rest of the X-Men, he hasn’t been the same mentally.
From the gist of what Iceman tells him, Juggernaut realizes that there are other survivors. He begs Iceman to let him see them. He won’t hurt them. He just wants somebody to talk to. Iceman can’t answer as his powers have expanded so that he’s covered himself in a big block of ice. Juggernaut breaks through it and sees a big metal door in his way. He tears it off, enters and finds a small community of people looking at him with mixed reactions. Some with disgust. Some with hate. Some with fear.
Quicksilver and Scarlet Witch advance. When Juggernaut pleads with them that he means no harm, they ask if he’s making some kind of sick joke. Toad steps in and chooses to address Juggernaut, as Toad is Magneto’s official successor. Juggernaut compliments how smart he was to have camped right under the Sentinels’ noses.
Juggernaut tries to apologize for all the death he’s caused, but Quicksilver gets to the point that Juggernaut has completely missed. By breaking through to this lower level and smashing apart all the doors, he’s doomed them all to endure the poisonous atmosphere and die just like everyone else!
Juggernaut turns around and walks of with his head down, knowing that he’s about to be the last living being on Earth and his own irrational, boorish behavior is what’s to blame. On his way, he passes by the frozen skeleton of Iceman, but pays it no mind. He just continues walking on into the underground darkness.