Jack is a very highly educated high school teacher at a private school for girls in New England. When Jack is falsely accused of having an inappropriate relationship with one of his students, he pleads guilty to a lesser charge and is sentenced to eight months in prison. Jack's mother, a crusader for women's rights and running an improvised "halfway house" for prostitutes, refuses to believe his claims of innocence and abandons him.
After serving his sentence, Jack wants to have a fresh start, which he finds when he wanders into a diner in Salem Falls, New Hampshire. Without revealing the details of his past, he is hired on as a dishwasher, assisting the owner in the kitchen. He begins a romantic relationship with Addie Peabody, the woman who co-owns and operates the diner with her father and is mourning the death of her young daughter, Chloe, from bacterial meningitis at six years old.
Under New Hampshire law, Jack is required to register with the local police department as a convicted sex offender. As this is a matter of public record, soon the entire town becomes aware of his past. Addie Peabody does not change her attitude towards Jack.
The novel also revolves around local teenage girls who experiment with Wicca: manipulative, disturbed Gillian, daughter of Amos Duncan the most prominent businessman in Salem Falls; Chelsea (in whom Jordan McAfee's son, Thomas, takes an active interest); Whitney and Meg take an interest in Jack. Although he does his best to stay away from them, one night he accidentally stumbles upon them in the woods while they are celebrating the Wiccan holiday of Beltane.
Because of his past and the prevailing attitude in Salem Falls that Jack should not be there, he is quickly accused of sexually assaulting Gillian. Due to his intoxicated state at the time, Jack is unable to recall where he was that night.
Jack is defended by Jordan McAfee and assisted by Selena Damascus. Throughout the trial, Jordan manages to cast reasonable doubt on Gillian's testimony. Meg, however, confides in Addie that she remembers Jack touching her in a sexual manner. Addie believes her because she thinks that "no woman would lie about something like that", and takes Meg to report the incident to policeman Charlie, who is Meg's father.
Clues begin to unravel that Gillian has been lying about the assault. Sources tell that she and her clique were taking drugs on the night of Beltane that cause hallucinations. The initial blood screening when Gillian was given a rape exam showed no evidence of drugs in her system. Jordan does not believe this and hires a private toxicologist to run tests on the blood samples, which reveal extreme amounts of a hallucinogen. It is also discovered through her previous psychiatric records that Gillian was known for being a compulsive liar as a child after the death of her mother.
Chelsea gets an attack of conscience, though, and mails "The Book of Shadows" (a witch's handbook, and proof that they are part of a witch's coven) to Thomas, who takes it to Jordan. Jordan then uses it against Gillian, who claims she "didn't want to be labeled a slut".
Jack is pronounced not guilty. After the trial, Meg reveals to Charlie that Gillian convinced them to make it all up, as a game, to see if they could ruin his life because Gillian was attracted to Jack and he turned her down. Her reports of Jack having touched her inappropriately are revealed through flashback to have been accidental contact with her breast while saving her from a fall. Charlie reluctantly agrees to protect her.
It is revealed that Addie, too, was gang-raped at sixteen by Charlie and Amos, so therefore Addie never knew the true identity of Chloe's father. Charlie apologises and Addie appears to accept this. Jack offers to move with Addie to New York, to reconcile with his mother. She agrees.
Jordan and Selena - who have been battling their mutual attraction - get together. It is revealed that Chelsea and Thomas conspired - via witchcraft - to do so.
The final twist is saved for the final paragraph, when it is revealed that Amos has been raping and otherwise sexually abusing his daughter, Gillian, since she was young, and as the novel ends, seems to continue doing so. It then seems likely that the semen found on her thigh is his, not Jack's.