On the run from authorities and trying to figure out a way to cure his gamma-irradiated curse, Bruce Banner enlists the help of Jamie Madrox, the Multiple Man. But things get out of hand when a lab accident creates another Hulk…and another…and another.
Bruce, Rick, and Monkey are getting mugged in an alley behind Billy's Billiards. Just before things get ugly, Jamie Madrox (The Multiple man) shows up and "disposes" of the would-be muggers. Bruce has hired Mr. Madrox, who works as a private detective, to locate a friend of Bruce's; Professor Singh.
Jamie takes the trio back to his office and makes good on their arrangement, giving them the location of Professor Singh. Bruce leads Rick (wit Monkey in tow) immediately to the Professor's lab even though it is the middle of the night. He has decided that it would be best to use the Professors equipment to try to "cure" himself of the Hulk without involving Singh.
They are all set up and about to begin with the Gamma Ray Emitter when one of the Multiple Man's more paranoid duplicates comes charging in to stop them. The dupe believes that they are trying to change Bruce banner into some sort of super-villain. He doesn't realize that Bruce is already the Hulk! The Gamma Ray Emitter begins emitting despite Rick's efforts to stop the process. Bruce Banner and Jamie Madrox's duplicate are both caught in the powerful gamma rays.
The original Jamie Madrox shows up in time to witness the two get bombarded with gamma rays. When it's over, the dupe thinks he has succeeded. Bruce, frustrated and a bit angry with the dupe, uncontrollably transforms into the Hulk. Rick hips the dupe to the knowledge that Bruce was already the Hulk and seeking a cure. The original Madrox chimes in that he had figured that out.
The Hulk decides he should smash his way out of the lab. His first crash into the wall causes him to duplicate in the same manner as the Multiple Man! He has become the "Multiple Monster"!
The Hulk attacks the duplicate Hulk and they fall through the wall to the city street below where they are both duplicated by the impact. Now there are four Hulks. All the Hulks keep fighting and smashing (and thus duplicating.) Each one has a different personality.
One of the Hulks wearing spectacles comes bak to the lab. He is the sliver of Hulk in which Bruce Banner's intelligence resides. He knows how to remedy the situation. He recalibrates Professor Singh's Gamma Ray Emitter and craftily gets the original Hulk (Hulk Prime) under the machine. Jamie Madrox initiates the machine and draws his paranoid duplicate out of the Hulk back into himself. All the duplicate Hulks are then sucked back into Hulk Prime, transforming him back to Bruce Banner. The whole process burns out the Gamma Ray Emitter.
With all of the commotion and destruction, Bruce, Rick, and Monkey know they don't have time to fix the machine and try again before the authorities arrive; they have to split.
All acknowledge that they have found a new friend in Jamie Madrox, the Multiple Man.