Many way the night when young, Bobbie and Mary Campbell would listen to their grandfather’s tales of the creatures that stalk the Scottish night. They giggled with joyful fear and snuggled in their mother’s arms, hearing of such wonders as the Goblins, who roamed the moors, the Red Cap, who lived in ruined towers of dead kings, and Black Annis, who lured children from their homes to carry their dead bodies around as she wandered the Highlands. The two children felt safe in their father’s cottage, safe from the evils of the night, but they were wrong.
Tonight, something strange happens. Bobbie and Mary, both asleep, are in a transparent sphere of energy, floating towards a glowing light, the silhouette of one woman close by. The dangers of the Red Cap and Black Annis may have vanished but there is still evil in the world, evil that doesn’t spare innocents like Bobbie and Mary, or Moira MacTaggert, who, in some sort of trance, follows the sphere of energy into the glowing light.
(the next morning)
Scott Summers and Sean Cassidy stand at the shore of Muir. They have scoured the island but found no trace of the night visitors Scott mentioned he saw, though X-Factor’s leader is sure that something attacked him and that it involved Moira somehow. Sean agrees; after all, that was why he wrote Scott in the first place. Though the night visitors are new to him, Moira had him worried for months now and, with Professor Xavier presently not on Earth, Scott was the only person he thought he could turn to. Sean finds it somewhat embarrassing, having no real clues, but he has a feeling of being at unease. Scott knows what his former teammate is talking about. He felt it too, the night he arrived, as if he was watched by someone that hated him. Sean decides to explain how it all began.
Usually, Sean sleeps rather well on the isolated island but, one morning, he woke up early and found Moira gone from her bed and some unnatural light flooding the room. He then found Moira in the hall, slumped against the wall, with no memory how she got there.
Scott says that sleepwalking is hardly unusual, but Sean answers that his instincts told him something was wrong, and there were other incidents.
Another morning, after a fierce storm, he found Moira’s boots caked with mud, as if she had been out, though both of them had turned in early. He followed her footprints in the mud, until, at the beach, the prints simply stopped, as if Moira had stepped into oblivion. When he asked her about it, Moira denied having been out at all.
Scott surmises that whoever or whatever attacked him must be connected, but, before they can further discuss it, they are interrupted by an agitated Moira. She informs them that she just received a call that the Campbell girl is desperately ill. Sean explains that the Campbells are tenants of Moira, a fine family, and invites him to come along so that he can see how Moira takes care of her people.
Soon after, the trio have reached the Campbell’s house and, while Moira examines little Mary, Sean and Scott are talking with her physician, a Dr. MacKinnon, who is rather baffled, as he saw the girl the day before and she seemed in perfect health. They are going to move her to the hospital today, but he wanted to consult Dr. MacTaggert for a second opinion, first. He fears that, if the child continues to deteriorate like this, she won’t survive the week. Unfortunately, he has no single clue where the infection came from.
Scott thinks to himself that he isn’t of much help there. He sees the parents in shock and Mary’s younger brother, Bobbie, also frightened and scared. Scott kneels down to the boy and offers him some comfort, telling him that the doctors will do everything they can to help his sister. Bobbie knows his sister is very sick and claims that the little people in the light did this to her. Scott asks the boy what he means by that but, before he can get an answer, Moira interrupts once more, asking him to help Dr. MacKinnon, as they’ll be leaving for the hospital in a few minutes. Somewhat desperate, Moira walks out of the house. Despite her medical knowledge, she doesn’t know what the girl is suffering from. She finds some comfort in the arms of Sean, who followed her and reminds her that she is doing all she can.
An uneasy darkness settles over Muir Island and Scott Summers lies asleep in his bed. Suddenly, a cold white light floats into the room. It swells and the hum of a deadly energy increases. Scott wakes up just in time to roll over to one side before a lethal blast originating from the light hits him. Before he can be shot at a second time, he destroys the floating light with a optic beam.
Meanwhile, Moira, once more in a trance, has gotten up, fully dressed herself and left the building. She walks towards the islands shore, where a big glowing light opens up in front of her. The light seems to welcome her, as it is warm and enveloping, and Moira steps into it.
Back at the house, Scott bangs at the door of Sean and Moira’s room to alert them of what has just happened, but, as nobody answers, he runs down the door. Next, he shouts Sean’s name, with a shocked expression on his face.
Elsewhere, Moira is in standing on a metallic platform, surrounded by lots of technological equipment. Someone asks her if the girl is infected and she confirms it. Just like they had expected, her brother rejected the virus, but it still thrives in the environment of the girl’s system. Moira directs her answers upward to the huge form of Master Mold. It is pleased to hear Moira’s report – the girl was born a curse, now she will die of it. Master Mold calls that just and nature’s way. It then congratulates Moira on her excellent performance, for now it can remove mutantkind from the face of the Earth.