Synopsis / Summary / Plot
In the middle of the New Mexico desert, Bruce Banner meets with his beloved Betty Ross and his pal Rick Jones. The reunion is quickly interrupted by a huge drill-like vehicle boring out of the ground; its yellow-skinned inhabitants capture Bruce and knock out Betty and Rick with shock-weapons before disappearing back where they came from. Bruce finds himself in a preserved Roman city, ruled over by the aged Tyrannus, at war with the Mole Man for control of Subterannea. The ruler requires Bruce’s help in creating a weapon to tip the scales of the coming battle, and he shows his captive his great secret: the Fountain of Youth. A drink from this pool rejuvenates Tyrannus and he gives Bruce a few drops to hasten his allegiance. But Bruce refuses to create a weapon so the dictator has him locked in a dungeon. Bruce vents his anger and is surprised to find he doesn’t turn into the Hulk; is the Fountain of Youth a cure for his condition? Meanwhile, Betty and Rick have obtained climbing equipment and descended into the underworld where they are captured and brought before Tyrannus, who uses them as hostages to force Bruce’s cooperation. Tyrannus reveals that he has constructed a gamma bomb from plans stolen from the army base; all he needs is the failsafe formula to activate it. Once Bruce has written down the formula, the dictator sentences him and his friends to be thrown into a lava pit. The sight of Betty in danger finally causes Bruce to become the Hulk. He rescues Rick and Betty and then goes to war against the Tyrannoids. Rick and Betty discover that the villain has activated the gamma bomb, and when the Hulk arrives he tears the enormous weapon to pieces. Tyrannus then enters in a giant mechanical battle suit, which Jade Jaws thrashes mercilessly, causing a cave-in which buries the Fountain of Youth. As Tyrannus goes into the shock of desperation at losing his source of life, Hulk turns back into Bruce and the three friends return to the surface.