The Double Florin
The Double Florin is a 1924 thriller novel by John Rhode, the pen name of the British writer Cecil Street. Like H.C. McNeile's Bulldog Drummond and Agatha Christie's The [Secret Adversary] the plot revolves around a Bolshevik conspiracy to destroy capitalism and western democracy. The title refers to the Double florin coin.
It was his second published novel and anticipated the introduction of his best-known character Dr. Priestley in his following book The [Paddington Mystery]. The conspiracy is being directed by Professor Sanderson, a brilliant mathematician. Sanderson is not himself a communist, but is manipulating the organisation to try and create a new order based on pure reason.