I found the first book in the series to be just okay, with tons of 21st century anachronisms. I'd just visited the Churchill War Rooms, and Mr. Churchill's Secretary didn't show me anything about Churchill that I hadn't learned from a two-hour visit to the museum. I'm a sucker for WWII history and the royal family, however, so I went on with book two. While I enjoyed the setting of Windsor Castle (and bumped it up a star for those fun descriptions), the plot felt more and more familiar to me. I haven't seen Foyle's War in years, but I agree with other commenters that the (view spoiler)[piano wire murder (hide spoiler)] was pretty much a direct lift from that show. And as the subplot with Maggie's family progressed, I felt more and more that I was watching Alias. The more fantastic elements of the Alias spy family plots (view spoiler)[ such as the mom-is-really-alive-and-was-a-double-agent reveal (hide spoiler)] were ridiculous on TV, and even more so in this book. 
 And (I can't believe I'm typing this) Maggie is no Sidney Bristow. She is ignorant and unprepared for basic undercover tasks like behavior in the royal household. She's a super spy, but she can't even find her way to the servants' dining hall. She's supposed to fly under the radar, but she creates a public scene at her first dinner with all the royal staff. She lets general dislike of a mean girl character keep her from following up on a hunch based on the fact (view spoiler)[that the Firench maid is a new hire, fresh from German-occupied France (hide spoiler)]. She can't keep the princess safe and allows her to be kidnapped. Like in the first novel, she's steps behind the villains up to the end and only escapes because the double-crossing villain suddenly waffles (view spoiler)[and fails to kill Hugh or Maggie even though the bad guys have been killing people left and right to get away with the princess (hide spoiler)]. She "succeeds" due mainly to luck, not much skill on her part. I don't normally compare book characters to TV or movies, but when you lift entire scenarios from a tv series, you're inviting comparison. 
 We keep being told how smart Maggie is, but she certainly doesn't show it on her second outing. If she were a normally clueless girl-next-door stuck into international intrigue, I'd have found this book more enjoyable. But as a super spy, Maggie falls flat. I won't be reading on to find out what happens when she (view spoiler)[parachutes into Nazi Germany and meets her super-spy mother (hide spoiler)].