Weakened by an imminent metamorphosis, Hulk falls under the Humanoids power. Fortunately, gamma rays irradiated by the Leader prevent the Hulk from turning into Bruce Banner, saving his life.
In a lab, the Leader discovers the bullet in Hulk's brain, and dissolves it. Learning what his enemy has done, Hulk accepts to help the Leader.
The villain wants the Hulk to obtain a device called the Ultimate Machine which holds the knowledge of the whole universe.
That device is in posession of a Watcher.
The Leader sends the Hulk to the far spot in the cosmos the machine is at. But when he tries to grab it, he's attacked by a powerful alien, Anphibious (AKA Qnax, the Xanterean).