I like a good alternate history, and this one treads that fairly well-worn path of exploring how things might have been if the Nazis had won. Set in 1952, Halifax had become Prime Minister in 1940 rather then Churchill, and consequently Britain made peace with Germany after Dunkirk. There was no Blitz, no Pearl Harbor, no Africa campaign, no Normandy landings and no Hiroshima/Nagasaki. The British Government operates as a client state of the German Reich, which is mostly concerned these days with the endless war in Russia and the power struggles in anticipation of Hitler’s death. America has remained isolationist
Sansom’s world building is based on extensive research into the mid-century period (there’s a bibliography at the back), and his general picture of things comes across as pretty plausible. Think of a very dull austerity Britain with added repression, anti-semitism and state-sponsored violence. His speculations about how the actual political leaders of the time would have responded to the situation are particularly interesting. I suppose one of the reasons why he had to base his book pretty far back in time was to ensure all the people he used as characters are safely dead in the real world, and therefore unable to take umbrage.
However, where this novel fell down was with the plot and characters. It’s a standard issue spy thriller plot, which draws together some fairly random strands to bring the narrative together. And none of the characters really come to life.