Jo Walton (2006) Farthing.
Farthing is an 'alternate history' detective story set in 1949 and is the first in a trilogy (with Ha'penny and Half a Crown) featuring Scotland Yard's Peter Carmichael.
Britain negotiated peace with Germany in 1941 and while the war still continues in Europe, Britain has almost returned to normal as she sits safely out of the conflict. But what is the price of continued peace in a world where traditional British tolerance is being undermined by those who desire a neo-fascist state with its concomitant anti-Semitism and repression of other political parties? Will Britain's Jews, resident and migrant, need to flee their only European safe haven?
Against a background of political flux, the 'Farthing Set', negotiators of the peace settlement, come together for what seems like a typical aristocratic weekend at 'Farthing', Lord Eversley's Hampshire country house. But all is not what it seems: Sir James Thirkie, one of the architects of the peace, is murdered, and the clues point to only one man, Lord Eversley's Jewish son-in-law David Kahn. So begins a fight by Lucy Kahn to clear her husband's name. Lucy is aided by a sympathetic policemen, Inspector Peter Carmichael of Scotland Yard, but he too has his problems: his bosses at Scotland Yard want the murderer brought to justice at any cost - even if an innocent man is hanged - and their political masters are prepared to use any means to ensure Kahn is arrested. Carmichael has his own secrets - he is homosexual - and this case could ruin him. In a world where justice has been compromised by political expediency, will David Kahn be able to escape the trap set for him?
This is a gripping read. The narrative alternates between the voice of Lucy Kahn (all aristocratic in a sort of mad Mitford way with nicknames and secret languages) and Peter Carmichael (politically astute Lancashire boy made good who must choose between hanging an innocent man and personal ruin). The alternating narrative works exceptionally well as it fills in for us the gaps which each narrator cannot know.
He sighed. "I found out that Kahn did it, whatever the evidence looks like and however much of it I had. I found out that I'm the kind of person who can compromise and keep on going. And last, but definitely not least, I found out that a farthing doesn't buy very much."
This book was so good that I immediately ordered the rest of the trilogy.
If you liked this... perhaps Daniel Silva's The Unlikely Spy (1996: a beautiful German agent loose in Britain in World War Two is tracked by an unlikely spy-hunter). Counterfactual history: Andrew Roberts writes about Britain making peace with Germany in "Prime Minister Halifax" in More What If? Eminent Historians Imagine What Might Have Been, edited by Robert Cowley (2001).