A ship of many lights soars through the night sky far above the Scottish Highlands. Those few who look up and catch a glimpse of the light might catch their breath in wonder, though wonder is not what should be felt rather but fear, for within the craft a mad plan of death and revenge nears its tragic completion.
Inside the ship, Callisto, Cyclops and Moira MacTaggert stand surrounded by Conscience and dozens of Servitors. The image of Master Mold appears on a big video screen, thanking Conscience for returning Moira MacTaggert at this critical point of the plan, but asking why they didn’t terminate Callisto and Cyclops. Conscience asks his master to trust him, neither mutant poses a threat to them anymore, for they have contracted the Retribution Virus and he figured they should spend their last moments watching him eradicate their mutant brethren. Seeing the image of the big robot, Scott becomes angry and says that he thought he had destroyed it months ago in Alaska. The machine answers that it is a Sentinel and, therefore, it can rebuild itself or have duplicates of himself. It can hide its mind in the smallest of transistors.
Conscience comments with “Inspiring, ain’t it,” getting Scott even more mad. Telling the cyborg-like creature to shut up, Cyclops releases a powerful beam against Conscience, but it harmlessly bounces off his metallic hide. Even worse, his body weakened from the virus infection, Scott feels like his gut is on fire. Still, he tries again to use his power against Conscience, who taunts him, saying that he is a good little mutant for keep trying to harm him. His optic beam getting weaker, Scott asks who he is and the overeager Conscience is happy to finally have been asked about his origin. Conscience states that he too is Sentinel, built by Master Mold to ease its loneliness. His brain engrams are based on Master Molds, which in turn are based on those of Stephen Lang. Scott Summers begins to tremble and, eventually, his beam again fades before he collapses once more.
Callisto and Moira rush to his side, fearing that Scott has succumbed to the virus. Moira sees that Scott’s system is trying to fight off the virus but it can’t. Guilt-ridden, she asks for forgiveness. With his constant grin, Conscience thanks Moira for the effective little killer she created and reveals that, in just a few hours, they’ll release the death spores – mutants everywhere will die in no time. As the two ladies turn Scott around, who has been lying face down, they notice his visor having come off. Scott’s eyes are wide open and glowing red, but they no longer fire his optic beam.
Meanwhile, at the house of the Campbell family, a happy place until their daughter fell ill and vanished into the night, husband and wife are talking about their concerns. It’s almost too much for them to take in, their daughter Mary missing and the doctors saying that she might be a mutant... Mr. Campbell tells his wife not to think like that; surely they will find her and they need to be strong for their son Bobbie. As if on cue, the boy stumbles into the living room, telling his parents that he doesn't feel so well. The Campbells are shocked – it’s happening again.
Callisto demands to know what happened to Cyclops, who starts coming around. Taunting the warrior woman about her manners, saying that his hormones would be in uproar if he had any, Conscience explains that it’s a side effect of the Retribution virus. As they die, their mutant powers start to fade, “Congrats, you’re going to die almost human.” Callisto leaps at Conscience but, before her fist can make contact with his face, she is hit by an electric charge from one of the weapon-carrying Servitors. Conscience reprimands her about her bad temper and further teases her, saying that she is about as effective against him as she was at saving the Morlocks from the Marauders. Holding her shoulder in pain, Callisto says she’ll make him pay, earning her another mockery from Conscience.
The artificial man goes on to explain their ideology. While Callisto protected the Morlocks and the X-Men and X-Factor protected the rest of mutantkind, nobody was humanity’s defenders. There is a war out there and humanity needs a defense. It has crawled from the mud to create beauty, art, literature; it has birthed Michelangelo, DaVinci, Einstein and Confucius. Without protection, all this would be wiped away by the upstart of Homo superior. Conscience knows that this is the way of evolution but this time nature must by stopped, for mutants haven given nothing. Due to their powers, he theorizes, they lack creativity. Mutants will not struggle – they’ll just exist and stagnate.
In its chamber, Master Mold follows Conscience narration on a video screen. To itself, it says that it recalls no longer the things Conscience speaks of. Apparently, his portion of Lang’s mind dwells on the esoteric, while Master Mold fixates on purifying the human race. It is the primary, the only objective. Mutants will be eradicated... no matter what the cost.
In the meantime, the Campbells have taken their boy to St. Andrews, where DR. McKinnon confirms their suspicion – little Bobbie is suffering from the same disease. Mrs. Campbell is confused, as the doctor had earlier told them that Mary’s illness had to do with her powers. The doctor confirms that. However, it seems that they were in error and there is no link between the two things. By now, Mary’s nurse has come down with the disease too. He suggests that the Campbells have themselves tested next and, leaving the two alone, he says that prayer might be in order for they have no single clue what’s causing the illness.
High above, Moira raises her voice, asking if it never ends. How can anyone speak of beauty and art in the same breath as genocide? All of them are human beings and they all deserve to live. Still weakened, Scott tells her not to bother. Stephen Lang was a bigot when he was alive; there is no reason his robot duplicate would act any different. Before Conscience can reply, an alarm sounds. A voice alerts Conscience to the events at St. Andrews, that two non-mutants have contracted the Retribution virus. Initial data indicates the virus to have mutated, now attacking all human physiology. The reactions to this news differ – Moira is devastated, feeling even guiltier than before, Conscience curses at the term ”mutated,” again thwarting his plans. Callisto, however, sees it as a small victory, saying they’ll have at least some form of revenge.
Before long, Conscience arrives in Master Mold’s chamber, where he boards a hovering platform to speak with his alter ego face to face. Conscience tells Master Mold that their plan must be abandoned for the disease can still be contained, as long as they don’t release the death spores. Master Mold disagrees, though, stating the spores will be released according to schedule. Believing this to be a joke, Conscience comments on Master Mold having acquired a sense of humor but they really can’t do it, now that humans are threatened by the disease as well. Coldly, Master Mold reveals that mediscan estimates 100% of mutants dying but only 92.4 % of baseline humans. The remaining ones will be carefully watched by it to ensure that no future mutants will be born. Sure, the toll is heavy but, at times, innocents must die for greatness to thrive.
Conscience is not convinced. After all, they are talking about billions of people. “Wouldn’t that be like throwing out the barrel because of a few bad apples? Like the baby going out with the bath water? The...” Conscience is surprised; finally, he has run out of cliches.