Synopsis
Bruce Banner and Betty Ross are in Paris for a conference at the Academy of Science; passing the Cathedral of Notre Dame, Betty spies a figure atop the structure but Bruce assures her she merely imagined it. It was no delusion, however: it was Quasimodo, descendant of Victor Hugo’s original and he spotted the key on a chain around Betty’s neck (good eyesight, huh?) that will open the door to vast riches for the misshapen monster. At the conference, Bruce meets with Professor Jacques Royale who gives him a box containing a formula he requested; as they head toward Bruce’s lecture hall, Quasimodo leaps out of a manhole and carries Betty off into the sewers.
Hiding his captive in a small cell, the villain turns to confront the pursuing Bruce. Bruce is torn between sympathy for a fellow monster and fear for Betty and the stress causes him to transform into the Hulk. The two giants clash and in the fracas the box containing Prof. Royale’s formula falls into a crack in the floor. Betty suspects the two monsters are fighting over the key she carries, which her father wants her to deliver to the French Minister of Finance. As the battle takes the antagonists away from her cell, Betty manages to escape by climbing up to a high window and outside, unaware she is being followed by Quasimodo’s pet bat, Salvatore. Meanwhile, at the top of the Cathedral, Hulk and Quasimodo slug it out in the bell tower with Jade Jaws sending his foe flying through a window. The hunchback is caught in the nick of time by Salvatore (who is a big pet bat) and carried off in pursuit of Betty. Hulk tries to catch his quarry but ends up plummeting into the Seine. An exhausted Hulk drags himself ashore and turns back into Bruce Banner. At midnight, Betty arrives at a closed Paris Metro station for her meeting with the Minister of Finance; he takes her aboard a train where her key and its twin which he holds open the secret compartment in the floor of a train car which allows them to transport gold bullion securely. Having lost her earlier, Quasimodo had Salvatore searching the city for Betty and now that the bat has found her he returns to his master.
Bruce heads back to the underground cell where he recovers the formula, which can cure him of being the Hulk. He meets Quasimodo and explains the purpose of the formula and that there is only a single dose. The hunchback tells him that if he looked normal he would not need to hijack the gold so Bruce hands over the bottle. Quasimodo drinks it and…nothing happens. Enraged with disappointment he orders Salvatore to kill Bruce and departs to proceed with his plans for the gold heist. As the giant bat is crushing the life out of him, Bruce becomes the Hulk and clouts the bat, heading down the railroad tracks in pursuit of the villain. Quasimodo leaps into the train cab, tosses the driver overboard and drives off. Hulk arrives, his mighty leap carrying him and his foe off the train where…the misshapen monster transforms into a normal man. Prof. Royale’s formula worked after all! Hulk stops the runaway train and runs off. He turns back into Bruce and the now normal-looking Quasimodo thanks him for his gallant sacrifice.