In the mist-shrouded marshlands of northern England, something ancient awakens with clockwork precision.

By day, Patience Worth appears merely a meticulous London librarian, but as dusk falls, she transforms into something else entirely—a relentless investigator with an attic sanctuary where newspaper clippings form a tapestry of mysterious disappearances spanning generations. With forensic precision and a mind that catalogs the smallest details, she ventures to Bolam Village, where whispers of "the cycle" hang in the air like the bog's perpetual fog.

The village holds its secrets close. Locals fall silent when she approaches, exchanging glances weighted with both fear and desperate hope that this stranger might end their nightmare. In the tavern, hushed voices speak of "the Ashworth boy" and events that recur "in threes," conversations that die when they sense her listening.

As she maps patterns spanning a century, Patience uncovers a chilling mathematical precision to the horror: twenty-eight years, plus or minus months, between incidents. Her wall of evidence pulses like a living thing as dawn breaks, revealing connections no one else has made.

What stalks Bolam Bog is neither fully beast nor man, but something that transcends such simple categorization—something tied to the land itself, to the village's oldest families, and to secrets buried deeper than the marsh.

Nine days remain until the full moon. Nine days before Patience discovers whether she is the hunter—or the hunted.