When forensic scientist Rhona MacLeod returns to her roots on Scotland's Isle of Skye, a chance encounter in the woods behind a nearby activities centre leads her to what seems to be a crime scene, but without a victim. Could this be linked to a group of army medics, who visited the centre while on leave from Afghanistan and can no longer be located on the island?

Enlisting the help of local tracker dog Blaze, Rhona starts searching for a connection.

Two days later a body is found at the base of the famous cliff known as Kilt Rock, face and identity obliterated by the fall, which leads Rhona to suspect the missing medics may be on the island for reasons other than relaxation. Furthermore, elements of the case suggests a link with an ongoing operation in Glasgow, which draws DS Michael McNab into the investigation.

As the island's unforgiving conditions close in, Rhona must find out what really happened to the group in Afghanistan, as the consequences may be being played out in brutal killings on Skye . . .