When a grisly murder occurs on the Isle of Lewis that bears similarities to a brutal killing on the mainland, Edinburgh detective Fin Macleod is dispatched to the Outer Hebrides to investigate, embarking at the same time on a voyage into his own troubled past. As Fin reconnects with the people and places of his tortured childhood, the beautiful island and its ancient customs once again begin to assert their grip on his psyche. Every step toward solving the case brings Fin closer to a confrontation with the dark events of the past that shaped - and nearly destroyed - his life.

Living again of the Isle of Lewis, the ex-detective inspector Fin McLeod is working as a security officer for a local landowner. While investigating illegal activity on the estate, Fin encounters elusive poacher and former childhood friend Whistler Macaskill. But while Fin catches up with Whistler, the two witness a freak natural phenomenon - a "bog burst" - that spontaneously drains a loch of its water, revealing a mud-encased light aircraft with a sickeningly familiar moniker on its side.

A young meteorologist checking a mountain top weather station in Kinlochleven discovers the body of a missing man entombed in ice. Cameron Brodie, a Glasgow detective, sets out on a hazardous journey to the isolated and ice-bound village. He has his own reasons for wanting to investigate a murder case so far from his beat. Brodie must face up to the ghosts of his past and to a killer determined to bury forever the chilling secret that his investigation threatens to expose.

Half-Scottish, half-Italian Enzo MacLeod used to be one of the top forensics experts in Scotland, and now he lives in Toulouse, working as a university professor. Divorced in Scotland and widowed in France, he has an estranged Scottish daughter and a French daughter he has raised by himself. As if his life isn't complicated enough, he soon finds himself unexpectedly on the hunt for solutions to some vexing cold cases thanks to an ill-advised wager about the power of forensic science.

Lovers and business partners Niamh and Ruairidh are owners of a small Hebridean company, Ranish Tweed. Their fabrics have become internationally sought-after in the world of fashion. But the threads of their relationship are beginning to fray. As they prepare for an important showing at a Parisian fabric fair, Niamh accuses Ruairidh of having an affair with a Russian fashion designer they work with - a fight that ends with Ruairidh storming off. Moments later, Niamh watches in horror as the car containing her life partner explodes in a ball of flame. With Niamh a prime suspect in the murder, the Parisian police hound her....