Gambit breaks into Angel's house and steals an ancient relic. Angel sees Gambit thieving, and he chases him outside where Gambit meets up with Mesmero and hands him the relic.
Mesmero tries to leave with the relic, but Magneto shows up and traps him using iron fence rails. "You have a lot of courage to hypnotize one of my men to do stealing for you."
Mesmero has Gambit charge up some of his cards, but Magneto tightens the bars around him, crushing him, saying "Release the Gambit."
Mesmero does and Magneto takes the relic from him, "I am going to find out if this was all worth it."
He pulls up the ground under Mesmero and pulls him along behind as he leaves.
—
At the Institute, the X-kids play a game of Mutant ball. Angel shows up and breaks up the game, while saying, "I need to see Charles Xavier."
Angel identifies Mesmero as the one that blasted him.
Xavier tells Angel about Mesmero, "He manipulated Jean into stealing the rings that formed the first key. And the Spiderstone is half of another key." He continued, "Now that Magneto is involved we have to find the other half of the key first."
—
At Magneto's base, Magneto is searching through Mesmero's mind to find answers, and he found out, "The relic is one-half of the Spiderstone and that when these two pieces are combined they form a key to release the most powerful mutant of all time, En Sabah Nur."
But at the same time, due to Colossus's carelessness, Mesmero escaped from there.
He became furious on Colossus, he allowed Mesmero to escape, and with the piece of Spiderstone.
He tells Colossus that they're going to London to stop Mesmero from getting the other half of the stone.
At the Institute, Rogue brings Ben's dinner, he's still in the bed while he just wakes up for a few minutes.
Kurt followed her. He tells her that Wolverine and Storm are out searching for their mother and that the others have gone to London.
She tells him that they aren't related, but Kurt says that they are and no matter what she's going through, he'll be there for her. Rogue ignored him, while she turned back towards Ben.
—
In London, the X-Jet arrives at the museum. Xavier asked, "Cyclops go in the back and tell their stowaway that we've arrived."
Cyclops fishes Iceman out of one of the storage compartments.
Magneto and The Acolytes head into the museum and take care of the security.
While the X-Men and The Acolytes mix it up, Magneto finds Mesmero and traps him in an elevator compartment.
Mesmero loses the Spiderstone and it's drawn to the other piece. When the two pieces meet and fit together they form a huge mystic spider.
Magneto tries his best to keep the spider from leaving the museum, but the spider is barely slowed down and drags Magneto behind it.
Mesmero is able to break free and chuckles to himself when he sees Magneto struggling with the spider.
The spider bursts free from the museum and lands on some cars close to Xavier.
Magneto tolds him, "Xavier, ask your crew to destroy the spider, no matter what it takes."
Xavier tries to reason, "We don't know enough about the spider to destroy it."
"I know enough, and that it is one key that won't unlock any doors." Magneto answered.
"X-Men, capture and protect the spider." Xavier answered differently to Magneto's demand.
Colossus, Sabretooth, and Pyro each take a turn at the spider, but it beats them to a pulp.
Mesmero runs into Xavier as he's trying to escape.
Xavier uses his telepathy to probe his mind and find out about Apocalypse. The X-Men get to the spider, but they have no luck stopping it.
It reaches a populated area and Gambit crashes into it with a double-decker bus. He climbs out and charges the bus with it still on top of the spider.
Angel flies over in time to see the huge explosion. The spider is slowed just long enough for Magneto to catch up to them. The X-Men and Xavier arrive to see Magneto trying to destroy the spider.
"Stop, don't destroy them," Xavier tells him. But Magneto replied, "I have to destroy the key." Using his full power, Magneto is just barely able to destroy the spider and the Spiderstone drops to the ground.
Xavier tells him, "You have done exactly what Mesmero wanted him to do, that the spider wasn't a key, but actually, a guardian created to prevent Apocalypse from escaping. Mesmero manipulated you the whole time knowing that you were the only one with enough power to destroy the guardian. Now with the spider gone, the Second Door will open."
Xavier continued, "If Mesmero is able to find the third key and release Apocalypse, our world is going to change forever."
After giving the warning, the X-Men return back to their Academy.
—
On a cruise ship in the Caribbean, most guests enjoy a party, but Amara feels seasick and is accompanied by Tabitha.
Bobby tries to impress Tabitha and Amara but inadvertently forms an iceberg. Scott interrupts, startling Bobby, causing him to almost fall overboard
Scott rescues Bobby, who faces Scott's anger. Tabitha notices Amara's condition is not good, and shares it with Ororo, who decides to check on her.
During breakfast, Tabitha tries to prank a complaining lady, causing a fire. Jean uses her powers to stop the fire, revealing her mutant abilities. Chaos ensues, leading to the exposure of other mutants on board.
Later, the atmosphere turns hostile due to anti-mutant remarks, prompting Tabitha to join Amara, who's in a weakened state.
As the ship docks at San Sebastian due to bad weather, Amara's condition worsens, and Tabitha, with Bobby's help, starts rowing towards the island in an ice canoe to get Amara the help she needs.
Amara, Bobby, Tabitha, Kitty, and Kurt, head to a hot spring to help Amara with her sickness.
Amara, diving into the spring, discovers a fissure that starts to rumble. The water becomes too hot, and as they escape, Amara surfaces, warning of the danger.
As the tremors hit the town, the group uses their powers to help those affected by the chaos. The locals witness the kids' abilities and begin to see them as heroes, cheering for their help.
As the day comes to an end, the kids are invited to a party, but Amara feels downbeat, believing she caused the volcano's activity. Suddenly, the volcano rumbles, before they can react, the volcano erupts.
Fires break out in the town as rocks and ash scatter. The kids try to contain the lava.
Amara realizes she's the only one who can stop the eruption and moves towards the crater. Storm arrives and attempts to stop her, but Amara, controlling the lava, falls into the crater during another explosion.
Storm fears for Amara's life but is surprised when Amara swims through the lava to shut down the volcano. The other kids find Storm alone, learning that Amara fell into the crater, leaving them in disbelief.
Amara miraculously rides a volcanic flare to reunite with the other kids, leaving them amazed. The islanders cheer the kids, and Storm, though pleased with the reception, remains concerned about their departure from the boat. Then they returned back to Xavier's Mansion.
At the unknown place, An unknown person breaks into the X-Men's files, specifically targeting Wolverine's data and triggering alarms. Escaping the guards, the intruder slides down the building and disappears into the sewers.
—
At the mansion, Wolverine conducts a tough exercise, causing dissatisfaction among the students. Bobby jokes about the exercise while others get trapped in a pit.
Two helicopters from S.H.I.E.L.D. arrive, prompting Wolverine to talk with Professor Xavier, who confronts him about S.H.I.E.L.D. 's suspicions regarding the break-in at their HQ.
Eventually, Logan boards one of the helicopters at gunpoint, unable to explain the situation.
Nick Fury confronts Logan, showing him his company footage "See, someone break-in with Adamantium claws, and DNA samples match with you Logan."
Logan was confused, while Fury introduced him to a scientist, "She is Deborah Risman."
"I was working with Hydra and their attempt to replicate the Weapon X program that created Logan." Deborah Explained her past work.
"Are you mad?" Logan was angry at them.
Deborah didn't give him an answer, she continued, "We've succeeded with the 23rd attempt, using your DNA to create a warrior named X-23."
She feels happy but also said while adding, "However, due to an error in the process, X-23 turned out to be a girl with emotional instability and hatred. X-23's uncontrolled powers raise concerns about the potential damage she could cause."
—
Meanwhile, X-23, while spying on the X-Men during their exercises, is reminded of her harsh training program and the lack of love in her upbringing. She's troubled by her emotional and behavioral problems and experiences conflicting emotions while observing the camaraderie and care among the X-Men.
—
At S.H.I.E.L.D. HQ, Deborah continued to explain to Logan about X-23's upbringing and her troubled past. She expresses her intention to correct her mistake by coming to S.H.I.E.L.D.
—
Meanwhile, X-23 lurks in the X-Men's institute and later knocks out Xavier in a surprise encounter.
—
Fury informs Logan that X-23 targeted the X-Men's files. Understanding that they are X-23's next targets, Logan decides to confront her. Fury, aware of X-23's capabilities, reluctantly gives Logan an hour to handle the situation.