Part of a stunning new design partnership between Puffin and the Imperial War Museum, this is an unforgettable story from the bestselling author of The Boy in the Striped Pyjamas. This special edition features a foreword from Eoin Colfer.

The day the First World War broke out, Alfie Summerfield's father promised he wouldn't go away to fight - but he broke that promise the following day. Four years later, Alfie doesn't know where his father might be, other than that he's away on a special, secret mission.

Then, while shining shoes at King's Cross Station, Alfie unexpectedly sees his father's name - on a sheaf of papers belonging to a military doctor. Bewildered and confused, Alfie realises his father is in a hospital close by - a hospital treating soldiers with an unusual condition. And Alfie becomes determined to rescue his father from this strange, unnerving place . . .