Thor meets an alien trespasser whose hostility and monstrous appearance belie his unexpected worthiness to wield his hammer, Mjolnir.

The real Captain America and his fellow prisoners attempt to escape their Skrull prison.

When an Avenger group visits SHIELD's special prison in the Negative Zone, they soon find themselves under siege by a mysterious enemy.

Ultron orders the Vision to lead his android impersonators of the Avengers in capturing the originals.

While dealing with the Red Skull's escape with his Sleeper robots, Captain America also investigates the villain's former henchman who seems disturbingly familiar.

With the Hulk apparently rampaging wild, the Red Hulk comes to the Avengers to request to join.