A newscaster is reporting how anti-mutant riots have occurred throughout dozens of cities in America over the kidnapping of Senator Robert Kelly. Professor X says that they need to find Kelly before an anti-mutant fever consumes the nation; and as they already know Magneto is the pulprit Cerebro will be of great assistance.
In a shipwreck, Magneto is holding Robert Kelly hostage. Magneto tells him that they both believe mutants and humans can't live peacefully and that a war between between the two is inevitable and Kelly's assassination will serve as catalyst. As he's about to kill Kelly Sentinels tear through the roof and grab the Senator- they're also improved, as they're made of plastic rather than metal rendering Magneto's powers nearly useless. Magneto attempts to fight them off using the metal of the shipwreck, but he's punched into submission and buried in rubble.
The X-Men, picking up signals from Cerebro, arrive to the shipwreck in the Blackbird. They find the shipwreck abandoned, as well torn parts of Sentinels, and Magneto hurt and without his helmet.
Kelly is brought to a secret lab of robotic scientist, Bolivar Trask, who wants a presidential authorization for using Sentinels in charge of controlling mutants. Trask orders a newly built Sentinel to bring Kelly back to his campaign headquarters but it refuses. Trask then turns to a rebuilt Master Mold whom informs him that the Sentinel is not defective and is following his orders. Master Mold wants to replace the brains of world politicians, including Senator Kelly's, with a computer.
Back at the X-Mansion, the X-Men realize they need to attack the Sentinels before they get too strong but don't know where to start. Storm points out that, on Genosha Gambit saw the face of the man in charge of the Sentinels and Charles decides to use Cerebro to enter Gambit's mind to discover the man is Henry Peter Gyrich. The X-Men ambush Gyrich, who was also the target of an assassination, and he flees into a building. Wolverine however catches up to him and pins him to the ground and the X-Men interrogate him, while also overhearing Trask on the phone saying that the Sentinels are not only out of control but also seeking to replace the brains of world leaders. Scott says he needs to help them as the Sentinels are now a threat to the world but Gyrich says that thousands of Sentinels have been created already.
The X-Men return to the mansion where Charles insists that Kelly must be rescued or else there will be a civil war, but some such as Gambit believe it's suicide. Right then Magneto, still recovering, enters the room and tells him that his dream of peace between humans and mutants was foolish and that if they try to rescue Kelly the team will be throwing their lives away. While some members were initially reluctant, such as Rogue, Gambit and Wolverine, ultimately the X-Men decide to take the Blackbird to rescue Kelly while Magneto quietly says that the brave are always the first to die.
Following Gyrich's tips, the X-Men arrive at Trask's hideout where they split up: Jean, Gambit, Scott and Wolverine infiltrate the factory while setting up one of Gambit's exploding cards as a bait to draw the Sentinels while Professor X (piloting the Blackbird), Jubilee, Storm and Rogue distract the Sentinels. They then destroy dozens of robots but with hundreds of Sentinels pouring out of the factory they're quickly overwhelmed, and the Blackbird is damaged and starts to fall. However, Magneto has followed them and uses his powers to stabilize the jet, preventing the Professor's death.
Gambit and Wolverine are ambushed by Sentinels and Wolverine attempts to make a sacrifice by putting Gambit outside the room while he fights them off. While the mutant manages to defeat dozens, more Sentinels keep pouring in and Gambit has to rescue them. Meanwhile, Trask is arguing with Master Mold, saying that he was designed to protect humans from mutants and thus he must protect humans from themselves. Jean and Scott attempt to rescue Kelly but are detected. However, a horrified Trask turn a machine with Frickin' Laser Beams to a propane mane, distracting Master Mold long enough to allow them escape.
Outside the Sentinels realize their master is in danger and return to the factory. Scott splits off from Jean and Kelly, who escape outside, to find Wolverine and Gambit whom succeeded in defeating the Sentinels. Using his Eye Beams Scotts digs a tunnel for them to outside but when they arrive Master Mold appears from the mountain. Professor X pilots the Blackbird, protected by Magneto's magnetic fields, into the giant robot and escapes through the ejection seat. Magneto tells him that they're even and that they shall meet again.
Later, at a press conference, Kelly reiterates that mutants are humans beings and that they should not forget that in attempting to control mutants that abuse their powers, they should not oppress mutants that use their powers for the good of humanity. With Kelly's influence, Beast is set free and later, Scott asks Jean to marry him, which she accepts.
This episode provides examples of:
- A.I. Is a Crapshoot: Master Mold is merely following its programming of protecting humans from mutants- but it has realized that mutants are humans and as such comes to the conclussion that its goal is to protect humans from themselves.
- Assimilation Plot: Master Mold plots to put the most important world leaders under its control by replacing their brains with computers
- Big Damn Heroes: Magneto saves Charles' life when the Blackbird starts spirling into the ground after being damaged by the Sentinels.
- Big "SHUT UP!":Kelly: Please, I have a family, children!
Magneto: BE QUIET!
- Big "WHAT?!": Senator Kelly's memorable reaction to Master Mold wanting to replace his brain with a computer.
- The Bus Came Back: With this episode, Beast is freed from federal custody and rejoins the team full-time.
- The Cameo: Ghost Rider appears among Gambit's memories.
- Cliffhanger: As Scott and Jean muse about their future together, they're watched by someone sinister.
- Crazy-Prepared: An entire line of Sentinels was made out of plastics and on standby in case Magneto ever attacked again.
- Curb-Stomp Battle: The Sentinels made of plastics deliver one on Magneto. He puts up a good fight at first, but he's overwhelmed by superior numbers.
- Early-Bird Cameo: Bella Donna appears among Gambit's memories. She'll appear in in Season 2's "X-Ternally Yours" as an antagonist.
- Elemental RockPaperScissors: The Sentinels sent to rescue Kelly are made of plastic, and as such the Magnetism Manipulation of Magneto cannot affect them.
- Enemy Mine: Magneto teams up with the X-Men against the Sentinels and helps Xavier destroy Master Mold. Afterward
- For Want of a Nail: With Senator Kelly's assassination, Mastor Mold's prime directive would be changed to the extermination of all Mutants. Preventing this assassination gives Master Mold the time to develope his logical conclusion, endangering Humans and Mutants alike.
- Friendly Enemy: "Did you think I would let you die alone, Xavier?"
- Friendship Moment: When Cyclops says they have to go rescue Kelly, Wolverine is the first one to voice support.
- Government Agency of Fiction: Gyrich works for the Federal Security Agency.
- HeelFace Turn: Senator Kelly learns the error of his ways and becomes a supporter of peaceful mutant-human coexistence. His first good deed is arranging the release of Beast.
- Jerk with a Heart of Gold:Wolverine: Sit down, kid. You're not goin'.
Jubilee: I'm not a kid anymore! I'm one of you, one of the X-Men, and it means more to me than anything in the world!
Wolverine: Yeah. That's what it means to me, too.
- Logic Bomb: What causes Master Mold to rebel is it has come to the realization that that mutants are humans, too, and as so he must protect humans from themselves.
- My God, What Have I Done?: Trask's reaction to Master Mold's plan.
- No One Gets Left Behind:Cyclops: I'm going after Wolverine and Gambit. I'm not leaving anyone behind. Not this time.
- Noodle Incident: Gambit once had an encounter with Ghost Rider.
- Not So Different: Magneto points out that he and Kelly both believe humans and mutants can't coexist peacefully.
- Outrun the Fireball: Played with. Jean, Scott and Kelly manage to outrun the fireball for some time but they are forced to use telekinetic shields to protect themselves because the fireball runs too fast. Somehow, Trask also manages to escape from the explosion.
- "The Reason You Suck" Speech: Magneto delivers one to Xavier."You've lost, Xavier. Admit it. Peace between mutants and normal humans is only a dream... your foolish dream. If you try to rescue Kelly, you'll be throwing your lives away for nothing."
- Silly Rabbit, Idealism Is for Kids!: Magneto's opinion of peace between humans and mutants.
- Sinister Surveillance: Incredibly Lame Pun aside, Sinister surveils Scott and Jean as they celebrate their wedding proposal.
- Turned Against Their Masters: Master Mold has gained sentinence and intends to take over the world.
- Waving Signs Around: Protestors wave anti-mutant sings in the news to protest Kelly's kidnapping.
- We Will Meet Again: What Magneto tells Xavier before departing.
- You Are What You Hate: Trask says he created the Sentinels to protect humans against mutants. Master Mold reminds him that mutants are human.
- You Fool!: Master Mold's reaction to Cyclops and Jean attempting to rescue Kelly.