Nathan's father has been arrested. He works for the Ministry of Defence and is accused of leaking top secret information.
But as he is dragged into a police car, he gives Nathan a message.
It leads to a riddle, but it's not from Dad. It's from an ex-Bletchley Park employee, Lily Kenley, and was written in 1940.
Nathan begins to follow the clues left behind by Lily.
But how can this war-time story link to his father's fate?
Hope for Dad's appeal is fading fast. He must solve the puzzle. Time is running out.
- Format: Paperback
- Pages: 224 pages
- Publisher: Scholastic
- Publication Date: 03/05/2012
- Category: Crime & mystery fiction (Children's/YA)
- ISBN: 9781407124612