Review by Ida, St Andrew’s CE Primary, Oxford
Score: I would give it 5 stars.

I really enjoyed that this book what set in World War 2, adding an extra bit of drama, danger and secrecy. The plot really made me wonder about real situations like this, and how it would feel to be the protagonist - Robyn. It was very thought provoking. It made me think: friend or foe?

Review by Martha, Bristol Hospital Education Service
I really enjoyed reading this book, because I learnt about the Bletchley Park mystery. I don't normally read history books based on true events, so this book is new for me. 

The time that it was set was interesting to me, because it was thrilling to learn about how they managed to live, when there was a dangerous war going on.

The character I found most interesting was both Mary and Robyn. Mary because she was so smart and was able to learn languages like Italian. This really helped Ned and Robyn solve the mysteries of Bletchley Park. Robyn was interesting because she is an adventurous leader of the group. She loves nature and the outdoors, and is curious, leading her to get into trouble with the Heron. She is brave, and stands up for herself, and likes to be a rebel and break the rules. She is also kind and caring towards Joy, the beautiful pigeon. 

I learnt that men and women at Bletchley Park were hidden figures who were very clever mathematicians and engineers. They used the Enigma computer to decipher the code that the German enemy had created. They wrote in code to hide their secret messages about when they were going to attack the British soldiers. I learnt about Professor Alan Turing. It was very mysterious at first, and then became very exciting and serious when the bombs started dropping on Bletchley Park. 

The friendship and teamwork between Mary and Robyn stands out for me most. I was shocked how grown up and independent the war made the children act.

I learnt about all the code breakers and dispatch riders, who risked their lives and travelled on motorbikes taking messages to the soldiers. I learnt that bombs were dropped by the Germans on cities, and on Bletchley Park, and that some children like Mary were evacuated from the cities to the safer countryside. 

I would recommend it to people who like stories about war, adventure, powerful girls and friendship.