In his luxurious home in the Rockies, Warren Worthington III aka the high-flying Angel, lounges in front of a large TV, watching a report that the Hulk has turned himself in to the authorities at Gamma Base for treatment.
He is interrupted by his girlfriend, Candy Southern, who tells him there is a call for him. On the phone is Warren’s friend and former fellow X-Man and Champion, Bobby Drake aka Iceman, who asks if he and his new flame can come visit. Warren immediately invites them over. He adds that he and Candy ran into each other in Sorocco and decided to… renew their friendship. Bobby tells him they will be there the next day, causing Warren and Candy to make the best of the rest of the day.
CBS’s Charles Irwin finishes his feature, live from Gamma Base, hoping that the latest attempt at treating Bruce Banner may prove successful.
Doc Samson commends him for his fair treatment of Gamma Base. Irwin asks if there are any chances of interviewing the Hulk. Taken aback, Samson tells him he doesn’t know what he is asking. The Hulk is like a bomb waiting to go off. Irwin points out he’s been in ’Nam and Angola. He doesn’t scare easily.
That moment, a hole is torn through the part of the wall close to them and the Hulk walks out, announcing he has enough of waiting. Samson realizes he has grown claustrophobic. Hulk orders them out of the way. Irwin didn’t realize he was so big. Samson tosses the reporter up onto the top of a truck, then tries to calm the Hulk down. The Hulk shouts at him that he talks too much and hits him, then reminds Samson how he tricked him and called him stupid. Samson admits he was wrong. The Hulk is definitely not stupid. In response, he gets hit once again as the Hulk shouts he still talks to him as if he is stupid. He hits Samson with both fists and shouts he hates that.
Hulk’s friend Jim Wilson comes running and asks what he is doing to the Doc. Samson assures him he is fine and the Hulk stops lashing out. Jim’s presence actually causes Hulk to calm down and Samson silently believes they still have a chance of curing him.
Early the next morning, the former Champion aircraft lands at Warren Worthington’s home. Candy welcomes Bobby and the young woman he has brought along, Theresa Sue Bottoms. Terri is speechless the moment she lays eyes on Warren, then gushes excitedly she’s read so much about him and when Bobby told her he knew him she knew she had to meet him. Bobby groans to Candy that this isn’t his day.
Meanwhile, halfway up a nearby peak, a buckskin-clad figure, hat drawn over his face, comes out of his cave and starts his way towards Angel’s aerie.
Candy and Bobby are in the pool, Terri is nearby. They are waiting for Warren. Candy remarks she hasn’t seen anyone gush like that since high school. She is surprised Terri Sue hasn’t gone in after Warren. Bobby half-heartedly tries to defend Terri.
Finally, Warren returns now in his Angel regalia as Terri asked him to. Bobby remarks to Candy that she has put more emotion into that “golly” right now than into anything she said to him.
Candy is distracted by the stranger trespassing and coming closer, a man carrying a strange weapon. Warren hopes for the best and suggest he may just be lost. Is there anything they can do for him? They can surrender and die! is the reply and the man fires an energy weapon a Warren and Bobby but luckily misses.
Warren orders the women to get into the house and lock themselves in. Terri wants to stay and help, but Candy snaps at her that they’d just be in the way. She drags her inside, where she sets up a camera to monitor the events. She figures the boys will be okay. Especially if Bobby is who she thinks he is.
Indeed, Bobby ices up. He figures helping Angel in the fight is more important than his secret identity. He tries to freeze the stranger. Addressing him by his real name, the stranger mocks this will not stop him. Energy emits from his hand to melt the ice and the two former X-Men realize he is not human either. That means the gloves are off, Angel figures, flies at him and hits him with a long beam. The stranger drops right into the pool, which Iceman then covers with ice.
Warren suggests Bobby inform the girls while he gets the cops. Bobby wonders if Terri will get off on ice as well. However, there is a rumbling noise and, an energy blast later, their foe is free, now revealed as someone looking very much like a human-sized Sentinel.
Unimpressed, Angel announces they can fight those things in their sleep. Bobby warns him that doesn’t seem to be an ordinary Sentinel. Indeed, the Sentinel grows to giant size as he agrees and announces he is the Master Mold. Sentinel supreme! And he shall rid the world of all mutants!
Angel asks for a delaying tactic and Iceman tries a trick he only ever used inside the Danger Room, sucking all the heat from the air near the Sentinel, thus freezing him. Unimpressed, the Master Mold realizes, this leaves Iceman vulnerable to his frigiblast. He blasts him with cold and chuckles at the irony.
He sees Angel flying upward and figures he is trying to escape. The Master Mold flies after him.
The two ladies watch horrified, though Terri Sue, unaware of Bobby’s identity, still doesn’t understand why the Sentinel went after him.
Angel deliberately leads the Master Mold away from the girls, as he isn’t sure whether Master Mold shares the ordinary Sentinel’s prohibition to harming humans. Now he has to figure out some way to save his own tail feathers. Like a ricocheting bullet, he darts in and out of the rocky canyons, but to no avail. The Master Mold simply smashes his way through the rocks.
This thing is like Iron Man and the Hulk wrapped in one, Angel fears, which gives him an idea. Gamma Base is only a hundred miles down range. He pours on the speed, figuring he can be there in minutes.
Soon, an officer at Gamma air control notices the two disturbances and calls an alert. A few minutes later, two Air Force jets scramble to intercept the two strange UFOs.
At Gamma Base, Doc Samson angrily shouts, asking who authorized the use of klaxons? Do they want to wake the Hulk? Jim Wilson tells him to look.
A moment later, the exhausted Angel lands in front of them and Samson asks what’s wrong with him. Angel just gasps, he’s coming! A moment later, the Master Mold fires at both of them and orders Doc Samson to get away from Angel. He only wants the mutant. Samson hits the Master Mold and is instantly hit back and flies past the Hulk, who has gotten up to demand what the noise is.
The Master Mold, who has captured the Angel, orders him to stay out of it. The Hulk is not having it. As the Master Mold takes off, Hulk jumps after him and ´grabs his foot. Samson leaps after them and tries to warn the Hulk but he misses the Master Mold and lands back on Earth where he is expected by a very surprised General Ross.
The Hulk attempts to dismantle the Master Mold, who tries to solve the problem by flying higher up into the atmosphere where the Hulk cannot breathe. The Hulk passes out but is still hanging on to the boot, as Master Mold flies toward a certain asteroid.
Sometime later Angel and Iceman awake and find themselves trapped in tube-shaped transparent cages. The Hulk, in another cage, is still sleeping. The Master Mold smirks that they have found their final homes. He refuses to answer Angel’s questions and laughs, something that surprises the heroes, then leaves the room.
That moment, the Hulk awakes. He has been put in the special reinforced tube meant for the Blob but for the Hulk it is little more than paper mache. As he breaks out, he also smashes Angel’s cage and Angel helps out Iceman.
They follow the Hulk, who smashes the metal door, and find themselves on an observation platform. They realize they are in orbit. Hulk doesn’t care. He has fallen from heights like this, not that that helps Angel and Iceman.
Angel announces he will look for a way off and tells Iceman to watch the Hulk. Unimpressed, the Hulk almost immediately walks off and Iceman follows.
Angel flies through another part of the fortress, marveling at the level of technology, including what he believes to be a fusion reactor.
In the other section, Hulk smashes through doors, despite Iceman’s protests. They find the Master Mold busy with a giant scaled version of Cerebro. Hulk shakes off Iceman’s hands and attacks Master Mold from behind.
The Master Mold blasts him way with a concussion blast. Hulk attacks again and the Master Mold fires a million volts at him. He marvels that the fallen Hulk is still breathing.
Iceman demands to know what’s going on. Real Sentinels don’t laugh or show surprise! The Master Mold replies he is indeed a Sentinel now, but before he died he was a man named Stephen Lang.
He was the head of Project Armageddon, a government study of mutants and was dedicated to their destruction, before he met death at the hands of the accursed X-Men, namely Jean Grey telekinetically crashing his gun ship. But the explosion did not kill him immediately. As the cowardly X-Men fled the burning space platform, he dragged himself from the wreckage and crawled to the chamber which held his greatest weapon - the Master Mold! If he was to die, all mutantkind would suffer for it.
But as with his other Sentinels, the Master Mold circuitry deviated too much form Bolivar Trask’s design. He did not merely activate the Master Mold. As he breathed his last, he became the Master Mold!
Baloney! comes the voice of the Angel, who has secretly joined them. When SHIELD came for the orbital platform, they found Lang. He’s still alive in a government hospital – a mindless vegetable! Whatever the Master Mold is, he is not Steven Lang!
The Master Mold is shaken by that revelation. His mind, his memories are Lang’s. He must be him!
Hulk decides he doesn’t care. He will smash him just the same. He proceeds to do so. The Master Mold falls and the Hulk hits him again and again.
The two X-men are disgusted and ask if he is ready to go now. He might as well go, Hulk scoffs. The robot will not bother him again. They leave the command chamber but, behind them, the hands of the Master Mold twitch spasmodically to life.
They finally find a life capsule. It will be a tight fit, but they figure all three of them should fit in.
That moment, the Master Mold contacts them and informs them that he has jammed all emergency capsules and set the reactor to overload. If he must die a robot, they will die as well.
Angrily, the Hulk wants to return to smash the robot for good. Angel insists they need to deal with the problem of their escape. Iceman throws a snowball at Hulk’s head. He keeps on goading the Hulk from the entrance of the emergency module. Hulk realizes he wants to trick him inside. They want to go? he scoffs. Then go! He kicks the emergency module out away from the station. The Hulk is sucked outside but holds on and stubbornly makes his way back inside.
Propelled by the Hulk’s kick, the escape module moves toward Earth and, as it enters the atmosphere, things get hot. Inside, Iceman tries to cool things down, hoping the breaking rockets will start soon. They do at the last moment and some debris from the station hits the module, finally falling into the Atlantic near Miami.
Iceman creates an ice raft for them and worries about the Hulk. They see an explosion in the sky and realize it was the Master Mold’s planetoid. They fear not even the Hulk could have survived that. Iceman hopes he at least got a few licks in.
Suddenly, the ice raft shakes as a green hand grabs it from below and an ill-humored Hulk drags himself aboard. He explains that the stupid floor came loose in his hands and he fell. The two mutants realize that’s what hit the capsule. He was grabbing its underside.
Iceman tells him he is glad he made it. Angel reminds the Hulk he promised his friends to return to Gamma Base. Hulk recalls his friend Jim is there and takes off to return to Gamma Base.
The two former X-Men hope that, whatever Doc Samson has planned, will work out for the Hulk. Angel remarks they better get back to the mountains. They still have to find out if Terri Sue gets off on ice – if Candy hasn’t killed her by now. Why him, Lord? Iceman thinks resigned.