Captain James Ogilvie of the 114th Queen's Own Royal Strathspeys might have been pardoned for expecting the cares of the Raj to remain in India while he finished a well-earned home leave in London. But a summons from the War Office brings the problems of security on the North-West frontier surging back. A lance-duffardar of the Kohat Light Horse is to appear before the Bow Street magistrate, but the charge is blatantly false, and Ogilvie sets out to learn who is behind it. His investigations lead him to the accused man's squadron commander, one Captain Soames, a cavalry officer with more expensive tastes than his army pay allows, who seeks to supplement it by liaison with the most notorious frontier bandit of them all - the dreaded Wolf of the Salt Range. Back in India, it is Ogilvie's distasteful duty to act as agent provocateur and lure Soames into showing his hand. But the passes into the Punjab are no place for straightforward flag-showing soldiering and when there are traitors in the camp the hazards are formidably magnified.