I just finished “A Matter of Justice” by Charles Todd. This is the 11th in the series featuring Scotland Yard detective Ian Rutledge. The books are set post World War I, and Ian was an officer in the war.
Rutledge is a very intriguing character since he’s still suffering from the war (I won’t tell you how) and trying to keep it secret so that he won’t be dismissed from his job.
On the author’s web page, there’s a contest to win a collection of the Ian Rutledge books if you’re interested.
I’m not in any way affiliated with Charles Todd’s publisher