"Princess Elizabeth's Spy" is the second of Susan Elia MacNeal's Maggie Hope mysteries. I enjoyed the first one, "Mr. Churchill's Secretary," so much that I was elated at the opportunity to review this book. It most assuredly did not disappoint.In this book, Maggie washes out in the physical requirements of being an undercover agent for MI-5 during WWII. Instead, she is sent to Windsor Castle under the guise of teaching advanced mathematics to the young Princess Elizabeth -- against whom a kidnapping plot has been uncovered. The thought is that Maggie can gather intelligence and send it back without the physical dangers involved in being behind enemy lines.The book is peopled once again with historical figures prominent and obscure, as well as delightful fictional characters. I was rather surprised by some of the events surrounding the mystery, which is tricky to do (I read a good many). MacNeal's prose is delightful and she puts readers right into the middle of events. Her research is clearly impeccable even as she takes creative license with events at real locations.I cannot recommend these books highly enough to admirers of historical fiction and mysteries alike.(Review based on uncorrected advance proof.)