When Charles Jacobs, a new minister, comes to town, little Jamie Morton is excited. Almost everyone in the tiny Maine hamlet comes to love Jacobs, his beautiful wife, or both of them. Things change all too suddenly when Mrs. Jacobs and her baby die in a gruesome auto accident. Half-crazed, the reverend denounces God and religion during a sermon, is banished from the town, and thereafter pursues successive careers as a sideshow huckster, and then a faith healer, fueled by his lifelong experiments with electricity. Jamie meanwhile, grows up to be a musician, and develops a drug problem, which ends after he is "saved' by Jacobs, who uses an unorthodox electrical treatment to heal Jamie and cure him of his addiction.
Afterwards, Jamie experiences strange side effects, including jabbing himself with sharp objects while in a fugue state, as if trying to inject heroin. This leads him to start looking into those that Jacobs has healed. As it turns out, many of them have experienced similar side effects and some have killed themselves and others as a result. Later, Jacobs contacts him; Jamie's childhood sweetheart, Astrid, has developed terminal cancer. Jacobs agrees to heal her, but only if Jamie will become his personal assistant for one last experiment. Jamie reluctantly agrees, and Astrid is cured.
Jamie helps Jacobs prepare for his final experiment: Jacobs has discovered something he terms 'Secret Electricity', an all-powerful energy source that he has been using to effect his miraculous cures over the years. He now intends to harness a massive surge of this energy and channel it into a terminally ill woman named Mary Fay, who he has relocated to his lab. Jacobs' plan is to revive Mary Fay after her death, not in the conventional manner, but in the sense that she will be clinically dead and yet able to communicate with Jacobs and tell him of the afterlife, and what fate befell his wife and child after their death.
The experiment works, but not in the way Jacobs intends. The revived Mary Fay does become a doorway to the afterlife, but to the horror of both Jacobs and Jamie, there is no heaven, and no reward for piety. Instead, the fate awaiting every living person is revealed to be "The Null", a dimension of chaos, where dead humans are enslaved for eternity by insane, Lovecraftian beings, the most powerful of which is known as Mother. When Jacobs collapses with shock and Mother attempts to cross dimensions and attack Jamie, he is able to kill Mary Fay, break the connection and escape the lab.
Later, many of the people cured by Jacobs go insane and kill themselves and others, including Astrid, who kills her partner and herself. Jamie, one of the few survivors of Jacobs' treatments, is left relying heavily on antidepressants and reflecting that no matter what happens, sooner or later he is going to die and end up trapped in The Null under the yoke of Mother.
