Synopsis
The story so far:- Eimin (and her now-dead twin Uriel) killed a Celestial with Thor's axe Jarnbjorn. In revenge the Celestials destroyed the Earth. But Eimin used Scarlet Witch (now also dead) to Rapture all mutants away to safety on Planet X. Eimin blamed Thor and the other Uncanny Avengers Unity Squad for the death of Earth, and the mutants believe her.
Wasp is the only non-mutant on Planet X because she was onboard the space ark when it all happened. She and Unity Squad leader Havok have been on the run for 6 years. During that time they've had a child Katie. They have been trying, with the secret help of Beast, to go back in time to change what happened. To that end last issue they broke the Tachyon Dam which has been preventing time travel. But Wasp got captured.
Breaking the Dam also let in help from other times, in the shape of Thor and Kang with a selection of refugees from timelines that have been wiped out by the destruction of Earth. Kang has an ulterior motive - he wants a future Earth to rule.
Eimin now addresses the ruling X-Council to warn them of the danger now that the Tachyon Dam is gone. Magneto arrives with the captive Wasp to tell them of Havok's plan. Cyclops, Jean Grey and Storm have also been looking for a way to save Earth. But Magneto, Eimin and Cable agree that the destruction of Earth can't be stopped (because the Celestials are too powerful), but messing with the timestream could wipe out Planet X. Cyclops and Storm agree to lead a team to stop Havok.
Alex Summers and Beast have met Kang's Chronos Corps. Havok can't understand how Thor could trust Kang. But Thor says he's tried every way he can to get Midgard back, and now Kang is his only hope. And Beast reminds Alex that Kang's future is at stake too.
As Beast discovered last issue, the Dam still exists in the past and so still no-one can travel back there physically. Kang wants to send the minds of the surviving Unity Squad members (which include Sunfire and Wolverine, captives of their fellow-mutants) back into their earlier bodies. Hopefully they can get their team to work together this time to prevent the disaster. (Instead of being split apart by the machinations of the Apocalypse Twins.) Magistrate Braddock can extract their consciousnesses, and Doom 2099 and Stryfe can send them back in time.
There's 1 big problem with that plan for Alex. He had intended for himself and Wasp to go back in time in person, and take their daughter with them. But this method will wipe little Katie out of existence (along with anyone else born on Planet X). Kang solves his dilemma for him. He disappears with Katie Summers out of the timestream, saying he'll keep her safe. But he'll only give her back when Havok does the job.
Ahab and Thor assure Alex they didn't know what Kang intended to do. Beast says they'd better see about rounding up the other Squaddies. Sunfire and Wolverine haven't been seen since Rapture day. But Iron Man 2020's sensors have located them.
Those 2 mutants have been imprisoned in Eimin's private throne room for the last 6 years. In special stasis cells which apparently have kept them in agony for all this time. Eimin still has her 2 remaining Horsemen of Apocalypse - the ex-mutants Banshee and Daken. (The other 2 were human, and died with the Earth, or beforehand.) The Apocalypse Twin has especial hatred for Sunfire and Wolverine. Not only were they mutants who opposed her and the mutant destiny, but they were also ex-Horsemen themselves - chosen of Apocalypse. (And Daken hated his father Logan even before Wolverine killed him.)
Eimin also hates Kang because of the harsh way he brought the Twins up. 1 of the objectives of her plan had been to deprive her 'father' of his Earth. She doesn't know that Kang has already arrived, and hopes to capture Havok before that happens. Then Daken will kill Alex. And they'll assassinate the X-Council and blame it on Kang. Then Eimin will be acknowledged ruler of Planet X.
The Chronos Corps split into 2. Ahab, Beast, Doom 2099, Havok, Magistrate Braddock and Stryfe plan to rescue Wasp while the Abomination/Deathlok, Iron Man 2020, the Earth X May Parker/Venom and Thor have gone after Sunfire and Wolverine.
But before Havok's bunch can set out, Wasp comes to them. She collapses, and the alternate-future Magistrate Betsy Braddock detects that she's being controlled by Psylocke Betsy Braddock. Cable, Cyclops and Storm break in, accompanied by Magneto and his X-Force (Blob, Pyro and Toad from last issue, plus this time Lady Avalanche).
Havok tells the others to escape with Janet Pym while he holds off the X-Men. Possibly Beast leaves with Wasp, because I don't see them later. But Cyclops quickly takes out Ahab and Stryfe, leaving 3 to face the X-forces.
It's Scott Summers vs brother Alex, and Storm against Braddock and Doom. Storm drops the Magistrate, and Doom takes her out. Then Blob sits on him. Cyclops has Havok at his mercy until Alex tells him about his daughter Katie, and that Kang has her hostage. Scott hesitates, so Magneto takes over - preparing to kill Havok.
Eimin is watching this from her throne room with Banshee and Daken. But she still doesn't realise that Kang's army is already here. Until Thor breaks a wall down and confronts her with his squad. Venom and IM 2020 disable Banshee and Daken respectively. And Thor prepares to kill Eimin as he did her brother in #16.