The Red Horse is the fifteenth and most recent (2020) in the Billy Boyle WWII series by James R. Benn – at least until the new one comes out in September. It is on sale right now in both the US ($1.99) and UK (£1.41).
I read and enjoyed many of the early books in this series as “real-paper-books” from my local library, way back when. What’s not to like with a young Irish-American cop from Boston, whose mom got him a supposedly safe job on the staff of a distantly-related American general? Especially when that general turns out to be Dwight D. Eisenhower, the job may not be all that safe, and Ike needs Billy to solve a murder or two…
But I sort of lost track of the series after I started reading e-books almost exclusively, because these tend to be $9.99 and up in the US, and almost never (with the exception of the first one) go on sale. So just be forewarned – if you get hooked on this series, you may need to cross your fingers for your local library to have them, or be very patient, or spend lots of money.
(And finally, after reading the blurb, I note that this book sounds quite a bit darker than I remember the earlier titles to be. Not that books set during wartime are ever exactly lighthearted, but… I’m going to be interested to see if that’s the case when I read it.)