General Ross shares classified videos of the Hulk with Betty and Bruce and asks Bruce to devise some weapon to combat or contain the Hulk. Ross is not pleased with Banner’s progress. Betty has anguish over her unspoken feelings towards Bruce.
Deep below the surface of the earth, Tyrannus watches Betty’s anguish and somehow reads her mind, determining to use her love for him to conquer the Earth. He reveals that he had been imprisoned here centuries ago by Merlin the magician and has survived by drinking from the fabled fountain of youth. He also has become a leader to the race of beings down there that were scientifically advanced. He was a master of black magic.
Tyrannus arranges his meeting with Betty posing as an archeologist and she decides to use him to make Bruce jealous. He asks her to show him some nearby caves. Bruce trails them suspicious of this “archeologist”. The trail ends against a boulder blocking the interior of the cave. Inside Tyrannus radios General Ross that he will hurt Betty if the General puts up a fight when Tyrannus’ army begins their assault. Without knowledge of any of this, Bruce and Rick return to the lab to transform himself into the Hulk. He smashes through the boulder but Tyrannus is ready, suffocating him with volcanic gas. Rick and the Hulk pass out and are captured.
As the Hulk comes to Tyrannus tells the Hulk he must comply with his orders or else Betty will get hurt. He complies. First, the Hulk is sent out into an arena as a gladiator for sport. The Hulk goes on a rage and begins to attack Tyrannus after defeating his opponent and is reminded of Betty. He backs down. Rick Jones is left alone and escapes.
The Hulk is then used for physical labor within the underground kingdom. It tires him and he spends his nights depressed in a cold cell worried about Betty. Tyrannus bores of the Hulk and tells Betty he will order his death. Rick, disguised as a guard takes Betty to the Hulk’s cell. As Tyrannus’ guards come for the Hulk he sees that Betty is safe and breaks out. Tyrannus rushes to the scene just as the Hulk topples the two main support columns keeping the path to the outside world open. The three escape and Tyrannus is trapped again under the earth.