A successful thriller author suffering from writer's block and grief following his wife's disappearance. He serves as the primary narrator and travels to a remote Scottish island in hopes of finishing his next book and healing.

Grady’s wife and a tenacious investigative journalist who vanished early in the story after stopping to help a stranger. Her absence drives the plot, and her history is explored through flashbacks.

Grady’s loyal black Labrador retriever who provides constant companionship and comfort during his owner's grief. He accompanies Grady to the remote island, serving as an alert system for danger.

A famous, deceased author who previously owned the cabin on Amberly where Grady stays. His legacy and unfinished manuscripts loom large over Grady’s stay despite him being dead before the story begins.

Grady’s literary agent and Abby’s godmother, serving as a maternal figure to both. She owns the secluded cabin on the Isle of Amberly and encourages Grady to take the trip to break his writing slump.

The ferry captain and unofficial sheriff of the Isle of Amberly. He transports Grady to the island and serves as a gatekeeper to the isolated community.

A mysterious woman living on the Isle of Amberly who bears a terrifyingly exact resemblance to Grady’s missing wife, Abby. She claims to be a local resident, confusing Grady and making him question his sanity.