The University of Chicago, years ago:
At a college mixer, Kitty Pryde is trying to flirt with a boy when she is telepathically contacted by Professor X. He informs her that Colossus died when he sacrificed himself to cure the Legacy Virus. Kitty breaks down and cries.
On the Roxxon Oil space platform:
The nano-Sentinel Alpha is intrigued to notice that the X-gene of his prisoner Colossus has been altered. That would explain the aesthetic difference of his steel form back in Nevada. He’s taken the liberty to restore the genome back to its original state. Unfortunately, the procedure is harrowing.
Phasing through the station’s floors, Kitty prays for Peter to hang on. Telepathically, she asks for everyone’s status. The others are battling Alpha clones but assure her they are fine.
Kitty finds Colossus and Alpha. She tries to hit Alpha, who briefly dissolves his face around her fist and reminds her that she cannot disrupt his technology with her powers. She instead disrupts the station’s computers. He agrees but points out that the procedure completed 0.34 seconds before she arrived. The weapon is finished. Launch sequence has been initiated. She is too late.
Several small missiles drop from the station. Alpha continues that Earthfall is in 4.8 minutes. Complete extermination of all human beings with an X-gene 16.3 minutes after. He’s also taken the liberty of activating this facility’s auto-destruct sequence. He dissolves, wishing her farewell.
The other X-Men find that his doubles also dissolve. Kitty informs them of the situation. She then examines Peter and finds he is in a very bad way. When Gambit points out same goes for their ride, Kitty snaps that the priority is stopping the missiles carrying the bioweapon. If even one gets to Earth, all mutants die! Storm promises she won’t let that happen and uses her new enchanted mallet Stormcaster to fly into space after the missiles.
Rogue joins Kitty to carry Peter, while Kitty frantically wonders where Puck is.
Actually, right where she needs them. Alpha Flight join with Storm to destroy the weapons but Puck warns a few still got though.
Over the Atlantic Ocean, Pyro rides on an X-jet, expecting the weapon while Iceman is waiting for the contingency.
Moments later, an Alpha ship lands on the Roxxon platform, courtesy of Sasquatch who offers them a ride home. Unfortunately, the self-destruction begins and the ship becomes pinned. Any chance of getting another ship? Kitty asks. Puck impatiently retorts that they have three heavy lifters. Get one of them to free it! Unfortunately, Sasquatch, Rogue and Prestige are all down. Colossus, still supported by Gambit and Nightcrawler, offers to do it. He can’t even stand! Kitty points out as she helps and orders the other two to wake up Rogue and Sasquatch. There’s no time, he groans as the countdown announces three minutes to detonation. There’s three minutes, Kitty deadpans.
On Earth, Pyro awaits the coming missiles and burns them all. Puck warns about another bunch going down in South America, but those are all fried by Storm.
On the platform, Rogue and Sasquatch are still out. They are out of time, Colossus decides and concentrates. With a scream, he transforms into his steel form, displaying the form from before he was changed.
He gets the debris cleared while Kitty orders the others aboard. Exhausted, he falls down and shifts to his human form. Kitty calls for help and Nightcrawler teleports Peter aboard. Rachel transfers the skill to pilot the ship from the unconscious Sasquatch’s mind to Gambit’s and they take off at the last moment.
At the Triskelion, Lydia Nance is imprisoned in a transparent holding cell. Iceman gleefully informs her that the spheres were all destroyed. Nance insists they can’t hold her here, to which Bobby retorts she plotted to kill a species. Something tells him they will find a reason. Nance insists they can’t hold her. Alpha will help her.
That moment, Alpha manifests in the cell, but Kitty had counted on that contingency and figured correctly that Alpha can be frozen, as Iceman demonstrates. And Lydia Nance is speechless for once.
Although Iceman figures that is the last they have seen of Alpha, he remains unaware that that the nano-Sentinel only sent a part of himself.
In the infirmary, an agitated Kitty stands at Peter’s bedside, ordering him not to die. Colossus awakes and weakly recalls that, the last time he almost died, she proposed. Well, she’s doubling down, Kitty replies happily. They are getting married!