Justice Jones, super-smart super-sleuth, is back for her fourth spine-tingling adventure! For fans of Robin Stevens, Katherine Woodfine and Enid Blyton.

It's 1939 and war has broken out. Everything has changed at Highbury House school. The pupils have to help cook, clean and wash up, for a start! Then a boys' school is evacuated to Highbury House, and the girls have to share the building. Justice and her friends are delighted that there are still mysteries to solve, however. Like: why can they hear voices coming from an empty room? And how can there be a face at the window two storeys up?

Then Justice faces her biggest challenge yet. Could there be a spy in their midst?

Elly Griffiths is a bestselling, prize-winning adult crime writer best known for the Dr Ruth Galloway Mysteries.