Thanks to specifically designed gadgets by Xavier, the X-Men recover very fast from the injuries they received in battle with the Juggernaut. Because his students performed so well against their recent enemies the professor announces that they all earned a vacation. The X-Men immediately start packing.
Bobby helps Warren to hide his wings under a special harness and Hank has to wear certain shoes to hide his oversized feet. Scott replaces his visor with a pair of ruby quartz glasses. After all of them changed into civilian clothes, Scott plans to offer Jean to drive her to the train, but Warren had the same idea and was faster. Hank and Bobby depart to the city and after all the others have left, Scott leaves to spend some time alone.
Dr. Bolivar Trask, one of the greatest anthropologists, is seen during a press conference. He alerts the media to the danger of mutants. Trask fears that mutants are hiding amongst society scheming and plotting to conquer the human race. Professor Xavier learns about Trask through the newspaper. The media hyped up everything Trask said and attached pictures of empowered freaks using human slaves. Knowing that public hysteria is the greatest enemy that mutants might ever oppose, Xavier calls a TV station and offers to take part in a public televised debate with Bolivar Trask.
The next evening the event is broadcasted and Xavier is the first to speak. He tries to explain that mutants aren’t a different race, but persons with powers and abilitys other than the average human. Since the causes for mutation are not known, everyone’s children could turn out to be mutants and ignorance, rumor and fear should not influence the way mutants are being treated.
Various familys are seen watching TV, but they don’t believe Xavier’s words. They are angered by being called ignorant and refuse to believe that their own relatives could be mutants too.
Next up is Dr. Bolivar Trask. He repeats his views on the mutant problem and already presents a solution. He has built an army of huge robots called Sentinels and demonstrates their power by calling Professor Xavier a dangerous mutant that needs to be incarcarated. (Trask does not know how close to the truth he really is).
A giant robot grabs the professor. Trask uses a microphone to call up more Sentinels that step into the studio, then he orders the Sentinels to demostrate their various weapons array in public. Surprisingly the robots refuse, they destroy Trask‘s microphone and stun the anthropologist with a single blast. The robots claim that Sentinels are superior and do not need to serve anyone; their destiny is to command.
Xavier realizes that Trask must have made error while programming the robots since he is no expert on cybernetic brains, and so he telepathically calls the X-Men.
Bobby and Hank are at the “Coffee a-go-go“ where they usually spend their free time. Bobby is trying to get a date with the waitress Zelda and Hank listens to the strange performance of Bernard the Poet as the professor’s message comes in. Quickly they rush outside and travel across the city on Iceman‘s slides.
Warren was having dinner with his parents in their luxury Long Island estate and excuses himself with having forgotten an important appointment. After he has driven a safe distance he changes into costume and takes off for New York.
Back in the TV studio the Sentinels section leader choose one of them to guard Xavier and the other people in the studio, while the rest depart with their creator Trask. It becomes clear that they still follow their prime directive of guarding mankind, only they plan to do it best by ruling them. They captured Trask because they need him to create more Sentinels.
After they left Iceman and Beast enter the studio and try to fight the one robot that was left behind. Yet the machine uses various heat and force rays and keeps the two mutants busy.
Scott Summers was across the town and has called a cab to get to the studio. He insists that that the driver should increase speed and suddenly as the cab takes a sharp turn he losses his glasses. As a result Scott briefly shoots his beams through the cab’s front window; fortunately nobody’s hurt. He gets out of the car and runs away followed by an angry mob that recognized him as a “dangerous“ mutant. Still as the crowd hears about death-dealing eyes from the cab’s driver they are frightened and stop the hunt.
Cyclops changes into costume and joins the battle against the Sentinel. Still the robot proves to be more capable than the three mutants until suddenly it starts to topple and falls down as if switched off. Xavier mentally controls the bystanders and orders them to leave the studio, since he wants to examine the robot.
Meanwhile Angel has reached New York as he suddenly becomes aware of the group of flying Sentinels with the captive Dr. Trask. They register him to be a mutant and three of the Sentinels are ordered to attack him, while the rest continue to bring Trask to their headquarter. Warren is able to outmaneuver the three machines but suddenly he is pulled down to a train by an invisible force. Seeing that the Angel no longer presents an attack the Sentinels are called back by the section leader.
Inside the train Jean observed the fight from her window, it was her that pulled down the Angel since he was about to be surrounded. She performs a new stunt she had been practising for months, she levitates herself out of the train’s window onto the roof near the Angel. Together they depart and join the other X-Men at the TV studio, where Xavier under a great strain is able to pick the robot headquarter‘s location from the cybernetic mind.
Inside their headquarters the Sentinels bring Bolivar Trask into a room called the Master Chamber. It was there that they were created and they order him to produce more robots. Dr. Trask is in total denial, he can’t understand that his creations no longer follow his orders.
Suddenly an alarm sounds and the Sentinels observe on a videoscreen as a car approaches their hide-out. Its passengers are Xavier and his students. Having reached the area depicted inthe defunct Sentinel’s brain they are surprised to stand on an empty field of grass and trees. Suddenly they hear clicking of metal and the ground starts to rise. The headquarters are below, inside the hill. Various defense mechanism start to shoot at the group of mutants.