When Mrs Paxton, related to the aristocratic Leigh family of Sussex, is found poisoned in her bedroom one morning, fingers point towards her artist nephew Terence Napier, seen leaving the house earlier that previous evening after a row over her will. Months later and Napier has never been found, but curiously a dead body is discovered in a train compartment, and scattered at the dead man's feet are the famous Leigh sapphires - a necklace owned by...