The Leader and M.O.D.O.K. had unleashed a Cathexis ray upon the heroes that had arrived to help, as well as hundreds of AIMarines, turning them all into Hulked-out versions of themselves. The Cathexis machine was basically the same machine that gave Leonard Samson and the Red Hulk their powers. The Leader revealed that all the Hulked-out-Heroes would soon die, because of the overload of radiation in their bodies. Bruce Banner and the other ‘smartest’ reconfigured the Cathexis machine to drain the radiation from the Hulked-out-Heroes, and so that the machine that's draining the radiation didn't malfunction or explode, Banner willingly absorbed the excess gamma radiation into his body. The machine started absorbing energy very quickly and Banner’s body could keep up with the absorption, so Samson (attempting to show that he was always a hero), walked to the machine and began to help Banner absorb the energy as well.
This turned out to be a poor decision on the part of Samson as his body could not contain the amount of energies that Banner's could. All of the excess energy burned Samson to a crisp and his charred body fell to the floor of the Helicarrier. The remaining heroes aboard the Helicarrier warned Banner to stop, as the energies he was absorbing would rob him of his freedom from the Hulk, but Banner knew the repercussions and told the others to get off the ship. Reed became worried about what the Hulk would do once he returned, only to have Amadeus Cho remind him, that this was what Banner had trained Skaar to do all along. The Heroes escaped from the Helicarrier and as the machine exploded, and the Helicarrier crashed into the ground. From the rubble and smoke stepped a renewed Hulk, once again shaking and cracking the Eastern Seaboard with each step. This was the moment Skaar had been waiting for.
Skaar and Hulk quickly began their brawl, with Skaar trying to anger Hulk by mentioning Caiera. This incarnation of Hulk seemed unaffected by this and brushed Skaar off as a mere annoyance... until Skaar reveals that Caiera had lived on through the planet, until he fed it to Galactus. This enraged Hulk and the two began to fight once again. Neither seemed to really have the upper-hand, but at one moment when the Hulk was down, Red She-Hulk stepped in, hit Skaar and told Hulk to run away. Naturally, Hulk refused and Skaar landed a massive blow against Red She-Hulk, sending her crashing into a parking structure containing bystanders. As Skaar wailed on Hulk, memories of Bruce's childhood flashed in his mind, specifically those of the abuse he had taken at the hands of his father. Still being beaten on by Skaar, Hulk released a sonic-clap, sending mounds of sand from the beach they were fighting on into and around the crumbling parking structure, saving the innocents inside. Skaar now saw that the monster Bruce had been training him to kill wasn't a monster at all. As he hit this realization, Hulk's emotions got the better of him and he laid Skaar to waste with a series of savage blows. Skaar reverted to his child form and told Hulk that he was done; Hulk was not the monster he thought. Hulk too returned to his human form and was struck with the emotion of all that had just happened. Red She-Hulk told him to go to Skaar, who was now quietly sobbing, and Bruce at first doubted that he could. As he reached out in apology, Skaar turned and firmly embraced him around the waist.