Another gripping story featuring John Mannering (aka 'The Baron'). A burglar is robbing a dealer's safe, but is interrupted. The burglar pulls out a gun and fires. Bullets tear into a man's chest. Some jewels fall as the gun is used. A girl screams. Next morning, John Mannering is contemplating persuading his wife back to bed. The telephone rings and he is informed of the murder. Another complex and dangerous adventure begins, which sees Mannering at his best and in France. Moreover, he has to try and prove the innocence of the dealer's assistant, who is the chief suspect, although Mannering is far from convinced ...