I'm going to speed through some parts of this since most of it fills the gap between Immortal X-Men and Rise of the Powers of X. I really enjoyed it though, more than I thought I would. I felt that Immortal was spinning its wheels a bit towards the end of its run but this gives us things to chew on and Luca Maresca's art is awesome.
We open with the preview pages of Destiny and Mystique attending a classical orchestra in 1899. As they're enjoying Elgar's show and the music swells into the ninth variation of the suite (Nimrod) Enigma appears before Destiny whistling along. She also sees images of the Hellfire Gala massacre, the X-Men/Orchis war, Krakoa, etc. As Destiny faints she says (via narration) that she finally understood what she learned four years earlier in Milbury House when she went down to the basement after Essex's death. She understood what Essex did in creating Enigma. She's known since that night in 1899.
We now get a flashback to the bench scene way back from Immortal X-Men #1 between Destiny and Mr. Sinister. She considered her options and 20 years after the orchestra she arranged this meeting with him. She tells him everything, about the four clones, how they're all vying for Dominion status but it's all a lie, that Essex will collect the data to construct his "digital ghost." She says they are on the same side and that they must be or else they are doomed. She starts to whisper in his ear and he seizes and falls to the ground. Destiny thought it was safe to tell him because her sight saw no immediate consequences. She was wrong as Enigma appears before her again. He took out Sinister. She realizes he exists outside her ability to predict but she also realizes he hasn't killed her yet. She tells Enigma that he won't kill her. He says nothing she does can affect him but she says he's not sure, that's why she's not dead yet. He says he won't take any risk he doesn't need to take but that the clones can't find out about him yet.
Enigma tells Destiny to stay away from him and he'll let her have a free run to Krakoa. She realizes he needs Krakoa too and he confirms, saying she and he must be on the same side. She says they're not on the same side, just going in the same direction. He calls her an amusing little creature and asks if she wants to know why Mystique leaves her. She becomes speechless as Mystique approaches her as she did in Immortal #1. Mystique wants to know what Destiny told Sinister and Destiny asks Mystique to trust her. That she'll tell her one day if she needs to but hopes it doesn't come to that.
Now we're in London, weeks before the X-Men's invasion of Earth. Mother Righteous is reacting to her failing to reach Dominion and she's angry. She's in her weird library, livid and now aware of Enigma's existence. Because the Mother Righteous in the WHR is basically an animated voodoo doll of herself she created to control, she starts feeling the pain of the beating Destiny is giving to WHR MR. She orders voodoo doll MR to beg for her life.
In the WHR Jean is still bleeding out (it's been a long time, no?). These are the other preview pages, Exodus saying he can't close Jean's wound. Destiny lands a nice uppercut and WHR MR is on the floor when Hope approaches, pointing her gun at her. MR, begging, tells Hope that she can help them. She says she lost and that they all have to deal with the digital god now. She says she can offer communication through the original MR between the WHR mutants and the real world. "I can find out about Mystique!" This stops Destiny's curb stomping.
Original recipe MR is now considering how to dissolve WHR MR but she turns around to find Orbis Stellaris and Dr. Stasis behind her. They try to capture her, they fight, she uses a spell to turn Stasis against Orbis.
It doesn't work cause MR is a novice compared to queen Selene. Selene conjures up dozens and dozens of what look like magical shards of glass above MR and then rains them down on her, slicing her up. Bleeding and on the ground with Selene approaching, MR uses one of her gold orbs to teleport away although not very far, just to a nearby alley. She's hurt and tries to run when suddenly a bunch of makeshift knives out of nowhere are thrown in specific spots so that they pin MR's cloak to a wall. She's stuck now. It's Charles! Using TK to control the knives and he has a lot more of them. He tells her not to move and that she's coming with "us." (He's got Sinister inside him still.) "Welcome to the X-Men" he says.
She's now pinned to the ground with the same knives which are made of mysterium and frozen iron to mess with her magic. They're in a No-Place which Charles says is hidden but not sufficient enough to hide from Enigma. Turns out he found her by contacting Shaw who sent Orchis (Stasis, Orbis, and Selene) to find her. Shaw appears on a monitor and in a strangely nice scene, Shaw tells Charles to erase all of this from Shaw's mind in case he's interrogated because he says Charles need to remain safe. Charles thanks him but is surprised Shaw cares considering his betrayal of Krakoa. Shaw, with a somewhat regretful expression, says Charles knew he was a rat but still put him on a sinking ship. He says Krakoa didn't fall because he betrayed it, he betrayed it because Krakoa had failed.
Charles then goes to a computer screen and says it's time to activate the clone. A naked Doug with a diamond on his forehead comes out of a cloning machine. Sinister, in Doug's body, says he's back. Charles announces that this has caused the remaining Sinister genetic dregs to finally be purged from Charles. Charles is now free of Sinister.
WHR MR, now prisoner and surrounded by Hope, Exodus, Destiny, and a few other mutants, tells them that OG MR has been captured and they can now communicate. Hope tells her to tell OG MR everything - Atlantic Krakoa, Phoenix dying, Jean, bleeding - but Destiny is all like "No! What happened to my wife?!"
In a scene that I found really funny, OG MR tells Charles that Destiny wants to know about her wife. Charles telepathically checks and learns that Mystique is actually now on Krakoa. He contacts her and is about to pass along Destiny's message but Mystique tells him to shut up and that she doesn't want to talk to him or Destiny. WHR MR tells Destiny that Mystique doesn't want to talk to her. Destiny is like what, why? But then Destiny figures out that Mystique must have read "the book." We see Mystique sitting on their bed indeed reading a book.
OG MR tells Sinister and Charles that she'll cooperate and tell them everything. Charles says then they can proceed. Weeks later the No-Place is now No-Place X thanks to Sinister, sitting at 0.00001 existence. By now Rachel and Rasputin have been recruited and Sinister is fully pretending to be Doug. Charles says that Destiny said with the X-Men at war with Orchis it's the best time to act as Enigma might be distracted. We basically get a brief planning meeting that lead to the missions we saw in the first issues of Rise and Dead X-Men.
Charles thanks Rachel for joining them and that for their plans to work she is essential. She says she gets it, that with Jean out of action there's no other choice. "... who else are you going to have on your team if you're planning to resurrect the Phoenix?" As Rachel powers up to start her mission (see Dead X-Men), Sinister tells Charles that Rachel isn't going to like it when she finds out Charles hasn't told her the whole truth. Charles agrees but says if they all live, he can live with that.