FBI agent Audrey Parker arrives in the small town of Haven, Maine, to solve the murder of a local ex-con, only to learn the enclave is home to people with supernatural powers.

Audrey tries to settle in as a new police officer in town, and she is joined by Nathan to investigate the seemingly random destruction of a local bar.

Audrey and Nathan investigate the local psychiatric hospital - where something has happened to make the patients placid, but sent a doctor insane. The phenomenon then spills across the whole of Haven, creating chaos.

Audrey investigates her family origins when she sees an old photo in the local newspaper of a woman who could be her mother, before the FBI agent and Nathan look into an epidemic that threatens the town's livestock and fields.

Old men begin turning up dead in the town, decomposing at an increased rate, so Audrey and Nathan try to track down the source of the phenomenon and reverse it.

Audrey and Nathan encounter another bizarre case when a member of the Haven Hunt Club is found dead in his car after seemingly being mauled by a wolf.