During a dark and stormy night on Muir Island, we see that Angel has come to see Dr. Adler, unaware that the real Doc is dead and the one he's speaking to is actually Mystique. Angel thanks Adler for all of the work he has put into the mutant cure. Adler says that it was only because of Angel's donations that he could create the cure, but now the time has come. It is only fitting that Angel himself is the first one to have the treatment and he is strapped down onto the operating table. Angel couldn't be happier, as he really wants to be "normal".

But suddenly Adler changes before his eyes into Mystique! He can't move and the treatment begins. As Angel writhes in pain, Apocalypse appears. Mystique tells him that the treatment is going well and soon he will have a new slave. Apocalypse tells her that her loyalty to him will be rewarded.

Meanwhile, the X-Men are also still on the island and hanging out in a pub with a lot of other mutants. They are discussing Adler's cure and how mutants don't need treatment. Rogue says she has accepted she is a mutant. Suddenly Angel walks into the pub saying that he's cured and that if any other mutant wants to become normal they should go and see Dr. Adler! He explains to everyone that he used to have wings but now they are gone. Cyclops says they don't need curing, mutants are normal people. But Angel disagrees and the other mutants want to have the treatment, too.

Back at Adler's lab Apocalypse watches Angel on a screen, but it isn't the real Angel. Mystique has shape-shifted into Angel's image. The real Angel is still at the lab and as he steps out from the shadows, he says that Warren Worthington is no more -now there is only Archangel!

Apocalypse intends to wipe out all life on the Earth and he will build a new world to his own liking on it. To do it, he has created four horsemen of destruction. Three other mutants hoping to be cured are turned into his slaves and along with Archangel, we now have Famine, Pestilence and War. Along with Archangel, this new group is sent out to start Apocalypse's grand scheme.

The X-Men have returned home and of course Gambit decides to continue being an idiot. He and Rogue are playing pool and he says if he wins he wants a kiss from the loser. Rogue once again reminds him that if she touches someone she'll drain their power, so he once again says that maybe it's worth it. Storm is watching a news report about a world peace conference in France, but as the conference is about to start they hear someone calling them all fools.

That someone is Apocalypse! He begins his attack as his horsemen also help out in the battle. The crowds flee and when the army arrives they are no match for this new evil force. Apocalypse also reveals he can change in size, becoming even bigger. He says anyone who stands in his way will be crushed.

The X-Men are all called to the war room where the Professor explains just what they are going up against. Clearly Apocalypse is a mutant who has been driven mad with his own power. There is no way they can try and reason with him so they will just have to try and stop him now. A team of X-Men goes out in the Blackbird whilst Xavier, Rogue and Jubilee are left behind. Rogue wants to know why she can't go and help but Xavier has a different mission for her. He noticed that the horsemen of Apocalypse were all mutants they saw on Muir Island. So he wants Rogue to go back there and visit Dr. Adler to try and find out if he had something to do with their transformation.

Meanwhile the horsemen go around the world doing things such as spreading diseases and destroying things. For example, War goes to an army base and has some missiles sent at him, but he uses his new powers to get the missiles to go and destroy some planes instead. Meanwhile Rogue arrives on Muir Island once again and asks Dr. Adler why there is a great big hole in the roof. He says that sometimes his experiments have unforeseen results.

He then says that he doesn't have to discuss his work with everyone but Rogue pins him down on the operating table and demands some answers. Mystique reveals herself and says that there is no cure, the machine hear actually turns mutants into slaves of Apocalypse. Not only do the slaves hate humans, but they also hate mutants, just as Apocalypse does. The only reason she is helping Apocalypse is because he would kill her if she refused. She also reveals that Apocalypse has a secret base in England, at Stonehenge. Rogue tells Mystique to lay low for a while as Apocalypse will want her dead for telling her this information. She throws her from the table and gets ready to leave, but Mystique pulls out a gun and blasts her.

She crashes into the machine and destroys it. Rogue says that they needed that machine -it may be the only way to change those mutants back! But all Mystique tells her now is that Apocalypse cannot be stopped and she then runs off. Rogue is going to follow her but the entire lab starts to explode so she leaves the building whilst she still can. Meanwhile, the X-Men team arrive where the horsemen are -England.

The group see Pestilence and Storm creates a thick fog around her. Whilst she is covered with this and unable to see, Cyclops blasts her and she falls off her horse. But then the X-Men see that the other horsemen are here and have to take cover when they start blowing things up.

Archangel saves Pestilence and then the horsemen all fly away, but Cyclops tells the other X-Men that they will follow them. Later on in the day, Rogue arrives at Stonehenge and challenges Apocalypse to reveal himself. He does so and says that she could have been the first one to serve his will if she hadn't of changed her mind at the last minute.

Rogue tries to attack him but he vanishes -seems that teleportation is one of his many powers. He then charges his fists with energy and blasts Rogue with lasers that she can't withstand and gets knocked back. They also destroy her jacket!

Archangel then returns, saying they have been defeated and aren't worthy of serving Apocalypse. He tells them that his creations cannot be defeated and that he cannot be defeated, but then gets blasted by a familiar red laser: the X-Men are here! Apocalypse shrugs off the blast and tells his horsemen to fight the new arrivals. A battle breaks out but the X-Men prove to be the superior fighters.

Rogue recovers and sneaks up behind Archangel before touching him, draining his power. He eventually manages to throw her off but he has become Warren Worthington again -and he sees what he has become. He tells the other horsemen to stop, but they continue fighting...

...so he ends up taking them out instead. Apocalypse sees that he really isn't worthy of serving him after all and tells the X-Men that they are only delaying the inevitable before using a hidden platform in the ground. Archangel then goes up to Rogue, who is still in pain having absorbed his evil side. Suddenly, the ground begins to shake.

This is because Apocalypse had a ship hidden under the Earth and he blasts off in it. It then vanishes in an instant. The three remaining horsemen also flee from Stonehenge. Archangel says that he wanted to be normal, but instead he became evil. Rogue says that she has his evil side in her now. Archangel starts to fly away and tells her that he hopes she can keep it under control -he couldn't.