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.