[1] It is based on a series of novels and short stories written by Edgar Wallace featuring the character of J.G.

Reeder, who had appeared in several film adaptations in the late 1930s.

Reeder is a mild-mannered employee at the Department of Public Prosecutions with an extraordinary gift for solving complex crimes.

He is played by Hugh Burden, working under the overbearing Sir Jason Toovey (Willoughby Goddard).

It is set in the 1920s, when the stories were originally written, and the graphics of the opening credits reflect this Jazz Age setting.