The night watchman at Hallams, the long-established Bond Street jewellers, is found dead with his head battered in, and a number of display cases have been rifled. Chief Inspector Burr picks up the trail, with the young Inspector Poole as his assistant.
But before long, the crime at Hallams is overshadowed by a mystery which stirs Scotland Yard into a frenzy of activity. Even the great Superintendent Fraser is aroused from his customary Olympian calm; but it is the detailed work of young Poole which eventually solves the double problem, links mystery to mystery and brings the clear light of day . . .