Holy Island by Alec J. Ross

Set against the haunting backdrop of Lindisfarne, a remote tidal island off the coast of Northumberland, this gripping mystery follows Detective Chief Inspector Ryan as he seeks to unravel a series of brutal murders that have shaken the tight-knit community. As the island is cut off from the mainland by the tide, Ryan must navigate a web of secrets, lies, and ancient folklore that threaten to obscure the truth. With the clock ticking and the body count rising, the detective must confront his own demons and the island's dark past to bring a killer to justice.