Having just read John Lukacs' excellent history, "Five Days in London, May 1940" which depicts the tense and uncertain week when the world could have tipped on its axis with Britain negotiating a peace with Hitler this seemed a natural follow up - a fictional account of what may have happened next had that been the outcome. Having read and thoroughly enjoyed the Shardlake series and (less so) "Winter in Madrid" I had high expectations. These were not entirely fulfilled but nevertheless I have not read many novels that caused me to think as much.
Some critics have complained over the individual depictions of historic figures (Enoch Powell etc.,) but I am prepared to give C.J. Samson the license to create a world and his intuition on these matters is, I think, acceptable the vast majority of the time.
More problematic from a novelist's point of view is some of the "explaining" that goes on both in the narrative and some clunky dialogue between the characters. I would rather be allowed to work it out how the history may have developed for myself than have it force-fed to me. Part of the problem here is Sansom's desire to have a vast array of "positions" on display - British colonialism, nationalism (see particularly Samsom's author's note and what it says about the SNP), race, old-school bigotry, communism, anti-semitism, fascism, civil service attitudes, sexist mores, unionism etc etc which, whilst ambitious doesn't always work. It seems too contrived within the format of a novel.
Having said that, the narrative itself kept my interest as it developed, particularly from the point in the story when the resistance ring is discovered and the subsequent escape and pursuit. The leading "heroes" are sympathetically drawn and seem to me to be acceptable portraits of pre-sexual revolution characters - think Foyle's War types to get an understanding of this.
Finally what, for me, is the biggest success of the novel is it made me address some attitudes in myself. The new year started with Labour politicians criticising the Government for not doing more to stop immigrants from other EU nations coming into the country. My reaction was depression - one party deciding to combat the "nasty" party by acting "nastier". I have long grown tired of the main political parties and the hypocrisy they represent. Russell Brand's solution holds much appeal. Yet what if by opting out we lose the voice of "decent" people? What may we allow to happen if we sit on our hands? Mr Sansom, your novel helped persuade me to join a political party.