Darkness in my hand - Frederic Lindsay

After a fraught dinner with his ex-wife and her husband, DI Jim Meldrum escapes early to drown the experience. Next morning he awakes in an expensive Edinburgh hotel with bruised knuckles, aching ribs and no memory of how he got there. Over by the window, a woman he doesn't know is getting dressed. If she is to be believed, they have spent the night as lovers. Later that day, the body of a man beaten to death is discovered in an unoccupied room of the second floor of the Hamilton Hotel. The room next to the one in which Meldrum woke up. Who was the dead man? And who killed him? Tormented by doubts as to what might have happened during the hours he can't remember on the night of the murder, Meldrum conducts his search for the truth.