Calvin Stewart has just retired from Police Scotland, but far from ready to sit in front of the fire with his slippers on. He has joined the small private investigation firm, run by a former colleague, Michael "Muckle" McInsh. Along with his friend, Finbar O'Toole.

Fresh off a case tracking down a runaway bride, they get a job to go north. A woman's husband disappeared almost a year ago while on a golfing holiday with some friends.

Now, the body of a man has just been pulled out of the water. This man had identification on him. Just not his own. It belongs to the missing man.

The woman wants answers. Where is her husband? And why did this man have his identification on him?

Calvin and Finbar are sent to investigate after the police investigation stalls. But this might be a bigger job than even they can handle. But Calvin Stewart has dealt with many killers in his career, but maybe not one quite as dangerous as this one...