The XPD of Deighton's enigmatic title [XPD] should be glossed as 'expedient demise'. His latest blockbuster is based on the factoid that there are three unaccounted-for days in Churchill's and Hitler's movements in June 1940. What happened, we are to believe, is that the supremos met in France where Churchill offered craven surrender terms, involving the carve-up of the Empire, sovereignty of the seas, and vast reparations. The record of the exchange—the so-called 'Hitler Minutes'—is dynamite. It must be suppressed at all costs and for ever. A decently off-stage Mrs Thatcher goes puce with rage at the thought of its being released: 'It would mean the end of the Tory party.' Any uncleared person who does find out the secret has his dossier stamped XPD….

XPD belongs firmly in the 'secret history of the war' genre. (Genetically it seems a mixture of The Mittenwald Syndicate, The...