Inspector Bill Mercer is a detective created by the British crime and mystery writer Michael Gilbert.
Gilbert goes on to say that "He was a man in his late twenties or early thirties, with a lot of dark hair, worn rather long,, and a thick, sensual face.
His appearance was not improved by a puckered white scar which started at the cheekbone and gathered up the corner of the left eye so that it seemed permanently half closed.
[2] Mercer was the ruthless protagonist of three connected, and rather grim, stories that appeared in Ellery Queen's Mystery Magazine in the issues of April, May, and June of 1979.
[3] By the end of the three stories, it is still impossible to tell what his motivating force has been throughout the series and whether or he has been successfully infiltrated into Henderson's gang as a long-term mole by New Scotland Yard's tough, ruthless, and cunning Chief Superintendent Morrissey.