A man is working at a research facility when some of his colleagues find an abandoned piece of technology under an insane asylum and decide to investigate it to study the history of computing. It is not a computer, but a difference engine. However, turning it on unleashes a massive wave of poltergeist activity all over Montreal. The first man to touch the machine died instantly as ectoplasm spewed out of it. Someone manages to destroy the machine and finds a corpse in the center—a woman from 1899 who was a powerful medium. With poltergeists unleashed across the nation, many people begin to hallucinate violently. One woman calls 911 reporting that a man follows her in her house wherever she goes, but when authorities arrive, they don't find any man there. A college boy reports that his girlfriend went into their closet and never came out, but the closet is not big enough to hold a person. These cases are dismissed as being related to insanity, but soon, they become widespread, so much so that the phones stop working, presumably because of the sheer volume of the calls. Video footage emerges of the supernatural events, such as bloody handprints appearing on a window and a girl being pulled into the ceiling. A young man on Reddit discovers that the color red repulses the ghosts, and as he spreads this news, a few people are saved, though much of the population is killed. The people who survive begin to paint walls red as a means of creating safe spaces. The man who worked at the facility recalls the story, explaining that his girlfriend Georgiana was killed, though he was not there when it happened and doesn't know how she died. He now lives in an abandoned hospital that has been painted entirely red, but he still sees Georgiana hovering above the river as a ghost. She does not want to kill him—not yet. The man explains that he plans on walking straight into the river to join her one day.