It's November 1941 in a Britain that lost the war: Operation Sea Lion succeeded, Churchill was executed, and the King is a prisoner in his own Tower of London. Detective Superintendent Douglas Archer, still working homicide for the Metropolitan Police under German occupation, catches what looks like a routine case, a well-dressed man murdered above an antiques shop, until the body's oddities point toward something far more dangerous than burglary gone wrong. Archer's investigation collides with occupation politics, the British resistance, and rival factions of the SS and the German Army, each wanting the case to go a different way. Len Deighton's alternate-history spy thriller.
Summary by Loreful, from public sources