The Ghost Squad — Gerald Verner

Mingling with the denizens of the underworld, taking their lives in their hands, and unknown even to their comrades at Scotland Yard, are the members of the Ghost Squad - an extra-legal organization answerable to one man only. The first Ghost operative detailed to discover the identity of the mastermind behind the buying and selling of official secrets is himself unmasked - and killed before he can report his findings to the squad. Detective-Inspector John Slade is his successor - but can he survive as he follows a tangled trail of treachery and murder?