The Windsor Knot

Using the queen as a main character and having her solve a crime was fun. She was very much the way I'd like to think she really is. But......Bringing in an important character in the very last part of the book seemed strange. I want to be able to consider such characters as the story progresses, not have them dropped in late in a sort of "Surprise! Gotcha!" Also, attempting to explain everybody and everything in the last part of the book is awkward and gets downright boring. The story line should be explained as the book progresses so that the conclusion comes smoothly without a lot of final explanation.