‘Ho. Ho. Ho’ laughs Cain Marko, a.k.a. the Unstoppable Juggernaut as he wishes the kids of Generation X – Jubilee, Chamber and Skin – a Merry Christmas before using his incredible strength to smash the ground and send the kids flying backwards. Jubilation “Jubilee” Lee boats that she has the Juggernaut, to which Angelo “Skin” Espinosa reminds the plucky Jubilee that they are up against the Juggernaut, ‘like on of the most powerful hombres on the planet’ and tells her that her fireworks are not gonna to do anything against him. Jono “Chamber” Starsmore declares that it is a good thing that the human students of the Massachusetts Academy have all gone home for Christmas, or else they would have to come up with a very interesting explanation as to why super villains are attacking the school and why some of the students have mutant powers.
Headmaster and former X-Man Sean Cassidy, a.k.a. the Banshee turns to his evil cousin, Black Tom Cassidy and asks him why he has attacked them like this and what he wants. Tom sarcastically tells Sean that he wants to be with his family for the holidays. Emma Frost, the other headmaster of the Academy and former White Queen of the Hellfire Club turns to her younger sister, Cordelia as Cordelia points to the unconscious man on the ground, declaring that he is Mondo and tried to kill her. Emma tells her sister to focus as Sean and Black Tom use their powers on each other, powers that cancel each other out.
Realizing he cannot harm his cousin with his sonic scream, Sean picks up a lead piping that was on the ground and declares that he does not need his powers to take care of ‘the likes of you’. Tom looks at the lead piping and jokes that it is ‘charming’ before asking what is going on with all the construction at the site and asking if this is not where Proudstar Hall used to be. Blocking Sean’s lead pipe with his staff, Tom tells his cousin that he should be ashamed of himself as he used to be able to beat him easily before he whacks Sean in the face hard with his staff and asking whatever happened to ‘that tough guy ex-spy?’
Emma starts to run over to Banshee until her sister asks her to stay with her, as they will kill her. Emma slaps her sister and tells her to be strong as the Juggernaut grabs Skin, who asks the villain if no one ever told him that ‘guys in dorky helmets should not throw stones’. Emma tells Cordelia to get back and stay down as Juggernaut is forced to let Skin go, who jokes that all his extra skin makes him squirmy.
Jubilee throws some of her fireworks at Juggernaut, who gets blinded by them and tells her that all she is doing is annoying him. Jubes jokes that she is happy to do her part when Cain is attacked from behind by Chamber’s bio-blast. Chamber introduces himself as they haven't met, and tells Cain that he can refer to him as “that guy who kicked my butt”. Juggernaut runs towards Jono and tells him to ‘bring it on’, which Jono does, increasing his bio-blast, deciding he has taken enough from the Juggernaut, Jono suddenly realizes that he has not used this much bio-energy before, but can somehow feel the Juggernaut weakening.
Suddenly, Jono stops and Gen X, Tom and Cordelia watch as the dust settles. Cordelia asks what it was that Jono did, to which Emma reveals that Chamber expanded more energy than he has ever done before. Black Tom calls to his friend Cain asking him if he is all right, as the dust clears they see Juggernaut standing upright, while holding an unconscious Chamber at his side, joking that he didn’t have what it takes to ‘run with the big dogs’.
Banshee turns to Tom and starts to threaten him in case Chamber is hurt, but Tom just smiles and reminds Sean that he cannot hurt him with his powers, when Emma steps forward and declares that hers can. She reminds everyone that Juggernaut’s helmet makes him immune to her telepathy, but Tom has no such defenses, and taking possession of Tom she orders him to use his energy staff on Juggernaut.
Black Tom is forced to comply and fires at Cain, who tells him to stop, reminding him that his energy cannot hurt him. Juggernaut manages to get to Tom and puts him to safety before turning to the Gen Xer’s and declaring that it was fun for a while, but that ‘playtime’s over’ and he clasps his hands together, causing a seismic shock to knock everyone out.
Meanwhile, at an exclusive boarding school in the Swiss Alps, former Generation Xer, the beautiful Monet St. Croix and her roommate Charlene stand outside the room of Charlene’s friend Tabby as police officers remove Tabby’s body from the school. Charlene cries, unable to believe Tabby was murders she asks Monet what they are going to do, but Monet offers no answer. Instead Monet tells herself that she cannot blame Charlene for falling apart at a time like this before recalling that she left the Massachusetts Academy to go to a normal school but no sooner does she arrive than girls start getting murdered.
Monet knows that Tabby was killed while she and Charlene were just a few feet away from her, knocking on her door. She wishes she knew who killed her, when the school Headmaster, Mister Delacourte steps up beside the girls, and startles them, asking what kind of headmaster he would be if he let his students gawk at such a gruesome scene. He asks Monet if she would take Charlene back to their room so she can get some rest, before informing her that he would like her to the come to his office so he can speak with her in private. Monet just glares at him.
Back at the Massachusetts Academy, Tom and Mondo have woken up and stand with the Juggernaut in front of Emma, Sean, Gen X and Cordelia who are all tied up in some metal construction equipment. Tom asks them if they are comfy and tells them not to look to Mondo to save them, as he can assure them that will not be happening. Tom then reveals that Mondo has never met any of them save Cordelia. Jubilee asks Tom what he is talking about, and Tom asks Cordelia if she would like to tell the story or if she should. Cordelia just smirks at Tom and he begins his tale “there once was a lass named Cordelia Frost …”
Cordelia met with Shinobi Shaw, who at the time was the head of the Hellfire Club’s Inner Circle, a group of mutants set on world domination. Cordelia came to Shinobi wanting to fill the role made vacant by her older sister Emma – the White Queen. Cordelia wanted to buy her way into the Inner Circle by giving them a powerful mutant she befriended then captured the Samoan mutant Mondo.
However Shinobi Shaw was not as impressed as Cordelia had hoped he would be and Shaw reminded Cordelia that the Inner Circle was a distinct hierarchy that one could not just buy his or her way into.
The negotiations between Cordelia and Shaw were interrupted by some more uninvited guests, who came not with a mutant like Cordelia did, but with weapons. The employer of these men, a man named Barrington had hacked into Shaw’s private computer, and announced that he would be taking custody of Mondo, whether Shaw liked it or not.
Tom ends his story by concluding with the fact that they all now Cordelia then came to them looking for help in rescuing her abducted Mondo. A furious Emma Frost turns to her sister and asks her if this is true, but Cordelia does not reply. Tom smirks at seeing Emma so annoyed, and reminds everyone that they rescued Mondo and he joined the team, only to betray them when he met them last.
Banshee asks his cousin how he knows all this, and Tom smiles, declaring that he is Barrington and after he had liberated Mondo from Cordelia he replaced him with a clone. Tom reveals that from the very beginning, it was intended for the clone of Mondo was to infiltrate the school, and while Bastion managed to kill the clone, the real one had been living with Tom all this time. Black Tom laughs when he boasts that he has always been good with kids, and tells them to just ask Sean’s daughter Theresa. Banshee tells Tom to ‘shut up or I will kill you with my bare hands’. Chamber tells Sean to calm down, before asking Tom to explain why they attacked Cordelia. Putting an arm around Mondo, Tom tells them to think of it was a Christmas present to his “son”.
Trying to squirm free from the restraints, Skin recalls to himself that he saw Penance creeping around in the woods and thinks that between the two of them they may be able to save the day. Mondo leans down to Cordelia and stroking her chin tells her that he has waited a long day for this. Tom declares that he knew Cordelia would go running to Emma, just as she always does when she is in trouble and jokes that they will have their nice family reunion for the holidays now. ‘After all’ says Tom ‘Revenge is a dish best served cold’.
Skin has almost broken free from the metal restraint and when he does he leaps out telling the ‘bad guys’ that they missed one. Juggernaut reminds Tom that he told him Skin was a squirmy one and Tom orders his allies to ‘get him’. Just them Penance springs onto the scene and slices through the metal restraint with no problem, thus freeing the kids, Sean and Emma. Getting ready for action, Banshee tells everyone to keep it together, as this is not an impossible victory, they can use teamwork and survive it. He tells Emma to telepathically link everyone up so he can map out a battle plan as Juggernaut asks Chamber if he wants another round. Jono replies that he doesn’t, but “she” is interested, and Cain turns just in time to see Penance leaping at him, claws outstretched.
Tom jokes to Chamber that he is going to let his poor mute friend try and slice off Cain’s helmet while he attacks him, and Chamber informs Tom that he can thank Sean for this strategy, as while Banshee’s powers do not affect Tom, Jono’s do. Angelo and Jubes approach Mondo and tell him that it doesn’t have to go down like this, and Jubilee reminds him that they used to be friends. Mondo asks the kids if they are deaf or just stupid, and reminds them that he has never met them before, which means as he turns his body into rock, he has no problems beating them into a coma.
In the air, Sean tells Jubilee and Skin to stand their ground as Mondo is not their friend, while Penance manages to claw off Cain’s helmet, and Sean swoops down to grab it before Cain can get it, leaving him open to Emma’s attack, and she does attack him, knocking him out. On the ground, Tom shouts that it was not supposed to end like this, and tells Mondo to remember the plan to get them out of here. Jubes and Angelo chase Mondo as he turns himself into dirt and starts to surround Tom and Cain, who as Tom reveals can use his powers to transport them out of here. Just before they leave, Tom tells the kids not to look so sad, as they will see their “Uncle Tom” again.
Gen X regroup and Emma decides that there is no point in going after them as she cannot track Mondo. Slumped over in the snow, Cordelia declares that his means that Mondo is free to come back and try and kill her again. “Thanks for saving my life, guys” mocks Skin to Cordelia, joking back “oh you’re welcome Cordelia, our pleasure. He asks Jono how he is doing and Chamber replies that he is a little woozy after taking on the Juggernaut, but that he will be okay.
Jubilee turns to Emma and asks her if that was really Mondo or if Tom was lying. Emma replies that she scanned Tom’s mind and it seems that he is telling the truth, although Emma admits that she wishes it were not the real Mondo. Sullenly, Sean remarks that this means Tom is raising another child …
Meanwhile, back at Monet’s school, Monet is sitting in Delacorte’s office and the headmaster asks Monet if she understands why he has asked her to come here privately. Monet replies that she thinks so, and Delacorte tells her that he wants to make sure she is all right after witnessing something so traumatic. Smiling, Delacorte reminds Monet that she is new here and wants to let her know that he likes to give all of his students special attention. With that, Delacorte’s eyes flash green and Monet realizes that he is trying to hypnotize her, however fortunately for Monet her telepathic powers are serving as a natural blocker.
Delacorte bares his fangs and declares that it is interesting Monet can resist his will, and jumping on her proclaims that they will have to do this the old-fashioned way. Monet was unprepared for how strong Delacorte is and is knocked off-balance, but she is no slouch in the strength department. Delacorte boasts that he will have Monet, but the powerful young mutant tells him ‘over my dead body’ and smashes him back off her.
Delacorte gathers himself and tells Monet that ordinarily he would take her up on that offer but that he was unprepared for her tenacity. Jumping out his window, he tells Monet that they will meet again. Monet tidies her hair while comprehending that she just fought a vampire, she thinks that she could call the Academy as some of the kids ran into Vampires not too long ago. However she thinks against it, as it is not like he bit her…but as Monet’s hand brushes against her neck, she pulls her hand into sight, and discovers blood!