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.

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.

Glasgow, 1965. Headstrong teenager Jack Mackay cannot allow for even the possibility of a life of predictability and routine. The 17-year-old has just one destination on his mind - London - and successfully convinces his four friends and fellow bandmates to join him in abandoning their homes to pursue a goal of musical stardom.

Cal Hooper thought a fixer-upper in a bucolic Irish village would be the perfect escape. After 25 years in the Chicago police force and a bruising divorce, he just wants to build a new life in a pretty spot with a good pub where nothing much happens. But when a local kid whose brother has gone missing arm-twists him into investigating, Cal uncovers layers of darkness beneath his picturesque retreat, and starts to realize that even small towns shelter dangerous secrets.