After the army shoots down their UFO, the evil Toadmen seek refuge in an underground tunnel and magnetically pull the moon toward earth, causing great disasters. Banner escapes imprisonment, confronts the Toadmen's attack and saves earth.

The Leader, a mutated super villain, learns that Doctor Banner's newest nuclear device is being transported to another military base by a train, and sends one of his Humanoids to attack the train and steal the invention.

Bruce Banner is hunted by the military for a crime he did not commit and The Hulk must fight for his justice.