Mrs. Salad is a big Cara Black fan, so she asked for this book for Christmas. Sure thing, hon.
The book also appeared on Tom Nolan's Ten Best Mysteries of 2020 list in the WSJ a few weeks back. So (this is probably a lapse in Christmas etiquette) I read it before she got a chance to. Sorry, hon.
Anyway, the title refers to Hitler's tour of occupied Paris in June 1940. He spent three hours visiting. (Everyone else in the book spends more time there.) Ms. Black constructs an elaborate what-if scenario around the quick in-and-out visit, involving Kate, an American female sharpshooter. She's near-suicidal due to the loss of her husband and young daughter in a Nazi raid on the Orkney Island village where they happily resided. An obscure branch of whatever they called MI-6 back then recruits her to a dangerous, probably hopeless, mission to assassinate Adolph.
Well, she misses Hitler. (This isn't totally alternate history.) But she accidentally plugs a Nazi Admiral, which puts a dogged German cop on her trail. And what follows is a cat-and-mouse caper, as Kate tries to escape Occupied France, The bad guys are pretty good at their jobs, but Kate manages to keep a step or two ahead of them through most of the book. She's much better at spycraft than her cursory training would lead you to expect. Complication: there are a lot of collaborators and traitors within the French citizenry. And the true nature of Kate's mission is only gradually revealed.