As the Second World War nears its end, the great economist John Maynard Keynes is at the peak of his career, despite failing health, and is seeking to establish a new international financial and currency regime for the post-war future. However, his assistant, Alec Harborough, discovers there is a plot to blackmail Keynes over events in his private life, the revelation of which could ruin Keynes's career and destroy his life's work.

Keeping the threat secret from Keynes in fear of his health, Harborough enlists Lewis Durrington to help him, a friend of Keynes and other members of the Bloomsbury Group. There follows a gripping race against time to track down the blackmailer and prevent him from carrying out his threat, a race beset by a series of failures, frustrations and dangers. But they must succeed, for it is not just Keynes who is in danger - world economic order is at stake.