Superman and Lois Lane are at home watching a television documentary on the Incredible Hulk; Clark Kent muses that he and Bruce Banner lead double lives: both have a secret identity, both were changed by explosions—for Superman, the destruction of his home planet Krypton and for Banner the gamma bomb which transformed him into the Hulk. In contrast Clark found a loving family in the Kents, while the Hulk has been hounded by the military to this day. Clark recalls his first meeting with the Hulk…and the story flashes back several years, to when both heroes were new to Earth. Banner is in his secret bunker when a nightmare about the Hulk triggers his change into his alter ego. Unable to stop the enraged brute, Rick Jones stands helpless as Jade Jaws bounds off to a nearby barbecue where he seizes the food, terrifying the crowd. Meanwhile, Clark Kent is interviewing a scientist who has invented a new type of seismograph when the device suddenly registers a series of small tremors. Clark dashes off to investigate…as Superman. Big Blue heads to the barbecue where he confronts Big Green and the Hulk punches the Man of Steel into space. By the time Superman returns the Hulk is gone.
Back in Metropolis, Lois Lane notices that Clark is researching the Hulk and heads him off by getting Perry White to assign her to cover the rampaging monster. When Clark finds out that Lois has tricked him, he asks for the assignment to interview Bruce Banner as a tie-in to Lois story. Thus the two star reporters soon find themselves in New Mexico. As Lois interviews people who have encountered the Hulk, she realizes that Rick Jones is always mentioned and determines to find him. In the desert, Rick lures the Hulk into a trap with a hologram projector and shoots a tranquilizer into Hulk’s mouth causing him to change back to Banner. Returning to the base, Bruce meets Clark Kent and both are surprised that Lex Luthor is also there, showing an interest in gamma ray research. Meanwhile, Lois has tracked down Rick who takes off as soon as she mentions Hulk. Superman then surprises Lois by showing up and informing her about Luthor.
Back at the base, the villain in question is touring the labs, flirting with Betty Ross and gathering information on the Hulk so that he can use Jade Jaws as a weapon against Superman. The next day, Lois gives Betty a lift in her car while warning her about Luthor’s shady reputation; suddenly the Hulk appears in the road, wrecks the car and carries off Betty. Clark is interviewing Bruce when word comes in about the Hulk. Clark races off to change into Superman while a stunned Bruce has Rick drive him to the scene. The stress of worry causes Bruce to Hulk out and he bounds off to find his double, a robot created by Luthor to lure Ol’ Greenskin into a trap. Hulk smashes the enemy robot to pieces so that when Superman arrives, he sees only the real Hulk standing over Betty. He knocks Hulk into the distance before Betty is able to tell him about the robot. An angry Big Green starts pounding on Big Blue, while the Army fires on both. Luthor advises General Ross to use the gamma gun against the two super-powered antagonists, trapping them in its deadly rays. When Hulk tells Superman that the gamma weapon is dangerous, the two form an uneasy truce to shut it down, Supes is able to hurl Hulk out of the radioactive aura and Jade Jaws bursts into the base and smashes the weapon to bits. As the personnel flee the building, Superman seizes Luthor. Just then the entire lab goes up in a blinding holocaust, which not even the Hulk could have survived. Rick later finds Bruce safe and sound, Supes reveals to Lois the truth about the robot, Luthor denies all knowledge, and Betty tells her father it was the Hulk who saved her.
Back in the present, Clark and Lois wonder where Bruce Banner is now, and if he is still enduring his own private hell. The answer: Bruce is in a western town, watching the Hulk documentary in a TV store window and when Betty’s death is mentioned, he breaks down in tears before heading on down the road…