When a man sets out deliberately to be the greatest cracksman of all time, he has set himself a task. When he tells Scotland Yard in advance of the exact location and time of his proposed robberies and defies them to stop hiin or capture him, he is really making things difficult for himself. And when, in addition, he makes enemies of his ex-fiancee and her ruthless, mur-derous father, and causes them as well as the police to seek his blood, he is liable to find that he is running along a Dan-gerous Edge where one false step will lose him his liberty if not his life. This is the history of ""Janus"", who makes such a perilous run. No one can move quite so fast as the self-styled ""Master of the Doors"", which is why he even finds time to make love as he pursues his exciting career along The Dangerous Edge. And that proves to be the mistake which leads to the end of Janus, the greatest criminal genius since Jack Sheppard.