by Stephen King

When Charles Jacobs, a new minister, comes to town, young Jamie Morton is excited. Almost everyone in the tiny Maine hamlet comes to love Jacobs, his beautiful wife, and his young son. Things change all too suddenly when Mrs. Jacobs and her child die in a gruesome auto accident. Stricken with grief, the reverend denounces God and religion during a sermon, is banished from the town, and spends many years pursuing a career as a sideshow huckster before pretending to regain his belief in God and becoming a prolific faith healer, fuelled by lifelong experiments with electricity. Jamie, meanwhile, grows up to become a musician and begins using heroin, which stops when he meets Jacobs again – Jacobs' unorthodox electrical treatment successfully cures him of his addiction.

After being treated, Jamie experiences strange side effects, including sleepwalking and jabbing himself in the arm with sharp objects while in a fugue state, as if trying to inject heroin. This leads him to start looking into the many others 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 achieve his miraculous cures over the years. He now intends to harness a massive surge of this energy from a lightning rod and channel it into a terminally ill woman named Mary Fay, whom 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". Mother inhabits the body of Mary Fay, transforming her into a grotesque monster, and attempts to kill Jacobs. Jamie shoots Mother with Jacobs' gun, and she leaves Mary's body. Jacobs has a fatal stroke, and Jamie arranges his body to make it look like he shot Mary. Jamie flees the scene and relocates to Hawaii. 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. He acknowledges and takes some small comfort in the possibility that the visions were "lies," but the novel ends with Jamie 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.