With the Avengers turned into Gamma Monsters, Hawkeye must convince the Hulk to help fight the Leader and the Abomination while Thor (who was unaffected by the Gamma Dome) fights the Absorbing Man.
Synopsis for "Gamma World, Part Two"
At the Leader's command, a larger and more powerful version of the gamma emitter from the Cube starts projecting an even larger gamma radiation dome over Las Vegas, mutating all of its inhabitants into monsters. Although the U-Foes and Zzzax remain securely locked up, the Avengers and the S.H.I.E.L.D. agents in the area are caught without their protective suits and become monsters as well, with the exception of Thor, thanks to his Asgardian physiology, and Doc Samson. Hawkeye and Black Widow are just barely able to escape the dome, which is continuing to expand at a steady rate. In the interest of saving the world, Hawkeye is forced to leave Black Widow behind while he goes to search for the one man who can figure out a solution to this problem: Bruce Banner.
How to find him? Why, just follow the sound of the explosions as the Hulkbusters are still on his trail. Just when it seems like they have finally taken him down, Hawkeye tips the scales in his favour. Once they're all gone he asks Hulk for his help in dealing with the gigantic gamma dome but Hulk is not exactly forthcoming considering some of the crap he's been through.
That sounds about as threatening to the Hulk as one might expect, and he starts laughing his ass off. Of course, this is exactly what Hawkeye was counting on and the anger immediately drains out of the Hulk, allowing Banner to reassert himself. But this is no laughing matter and the two of them get straight to business.
Meanwhile, Thor is brought before the Leader to serve as entertainment by squaring off against the Abomination. He calls the Leader out, demanding to know what gives him the right to lead, sending the Leader into a full-on rant distracting him long enough for Mjolnir to return to his hand. This is exactly what the Leader wanted him to do and the Absorbing Man appears to take on the properties of the hammer. As Absorbing Man hurls Thor down into the streets below for the other gamma monsters, Hulk squares off against the Abomination and Hawkeye, having been previously inoculated against the effects of the gamma radiation by Banner, shoots the mutated Avengers with specially-designed arrows that revert them to their previous forms. Absorbing Man appears to have the upper hand but that quickly disappears when Thor asserts control over his body in the same way he is able to command his hammer. He sends Absorbing Man upwards where he smashes into the Leader, who has activated a battle robot in order to fight Hawkeye and the Hulk.
Hulk smashes the gamma emitter and hurls it into space, collapsing the green dome and saving the world. Everyone returns to normal and it seems that Doc Samson will survive his ordeal. Hawkeye's sky cycle camera has captured footage proving his innocence and S.H.I.E.L.D. is willing to reinstate him as an agent, but he has learned his lesson after being thrown under a bus. He also refuses to join the Avengers; on account of how easily the Leader took them all out. Thor convinces the Hulk to rejoin the team, on condition that Hawkeye does. The Abomination is picked up by Baron Zemo, the Enchantress, and their rapidly-expanding team of supervillains.