The Disappearance of Alistair Ainsworth by Leonard Goldberg

A good old-fashioned whodunit featuring Sherlock Holmes daughter, Joanna, Dr Watson, and his son. Alistair Ainsworth is a cryptographer in possession of many British war secrets. It is discovered that he's been kidnapped and the race is on to find him before the Germans break him. Joanna uses the investigative skills inherited from her father to track the clues and solve the case.
I probably would have enjoyed this book more if I'd read the previous two novels in the series. I had a hard time connecting with the characters. They just seemed flat with no personality. This one was just ok for me.