Spurred by a John J. Miller article at National Review, I picked up a Kindle version of Daniel Silva's first novel for the unlikely price of $1.99! (Nowadays it goes for $4.99, which is still a pretty good deal.)
It's a World War 2 spy thriller, centered around one of the war's big secrets: where the Allies planned to invade France in 1944. The Germans are deeply (and correctly) suspicious of the quality of information they're getting from their existing spy network, so they activate one of their sleeper agents, "Catherine", a deadly and beautiful woman working as a nurse. She targets a young widower American engineer; he's been recruited to work on massive concrete structures, the Mulberry artificial harbors. The Nazis don't know what they're for, but if they figure it out, it could be an important clue, leading to the defeat of the invasion.
The "Unlikely Spy" is history professor Alfred Vicary, personally recruited by Churchill to ferret out agents like Catherine. What ensues is a cat-vs-rat thriller, eventually resulting in a high-seas shootout. Lots of violence, some sex, and a twisty ending you might not see coming. (I detected that there would be a twist, but didn't know what it was.)
There's an interesting mix of real characters (Churchill, Hitler, Himmler, Canaris) underlying the fiction. Much of the subtrefuge related in the book actually happened, too. (For example, Patton's First United States Army Group and MI5's Double-Cross System.) The fictional characters are well-crafted, even the Nazis are recognizably human. Well, except for Hitler and Himmler. Understandably.
Yes, we know how it comes out. Allies win. This doesn't detract from the book, it's still a fine page-turner (or screen-swiper).