Rating = 3.5 starsIn which the mystery is solved surrounding the disappearance of Flavia's mother during World War II. Also in which Alan Bradley prepares to take the series in an entirely new direction. This is a wise move. Life at Buckshaw is growing stale, and it's time for Flavia to take her chemistry skills out into the wide world. After all, she is almost twelve years old, and beginning to show signs of growing up. This works best as a just-for-fun sort of read. I thought the mystery and its resolution were a bit weak. The set-up is intriguing, with special code phrases and a murder on the train tracks and a revealing old home movie which Flavia discovers and then develops using her chemical cleverness. However, when we finally get to discover why Harriet (Flavia's mom) disappeared and who was involved, the revelations are sketchy. Bradley doesn't develop a clear picture (so to speak) of what went down (so to speak) all those years ago, what exactly Harriet's mission was, and what the villain(s) did. What makes the book worth reading is the playfulness you've come to expect from the Flavia de Luce series. Yes, Flavia is maturing, but she's still devious, and her imagination still takes her where no one's imagination should ever go. In this installment, she toys with the possibility of becoming a young Frankenstein and attempting to reanimate the dead. She decodes secret messages written in bodily fluids. She asks inappropriate questions such as, "How long does it take a person to bleed to death?" And as always, she's an unrepentant snoop. Fans of the series will not be disappointed. I'm looking forward to discovering how Flavia fares as she moves out among people who are not yet familiar with her precocious and pesky ways.