The Twenty-One Clues is a 1941 detective novel by the British author Alfred Walter Stewart, published under his pseudonym J.J.

[1] It is the fourteenth in a series of seventeen novels featuring the Golden Age Detective Sir Clinton Driffield, the Chief Constable of a rural English county.

It was published by Hodder and Stoughton in London and Little, Brown and Company in the United States.

[2] Two bodies are spotted by an engine driver in some bracken close to the railway line.

A man and a woman, unmarried to each other and rumoured to have had an affair despite their respectable backgrounds, have apparently taken part in a suicide pact.