Ruth Eastham Knihy

Alex's grandfather keeps forgetting things. Desperate to help him remember, Alex starts collecting old photographs. But as Alex digs into his grandfather's past, he stumbles across secrets that have been buried since World War II. Uncovering the truth could save Grandad... but it might also tear Alex apart.

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 Lily Wilson, and was written in 1940.