The day the First World War broke out, Alfie Summerfields father promised he wouldnt go away to fight - but he broke that promise the following day. Four years later, Alfie doesnt know where his father might be, other than that hes away on a special, secret mission. Then, while shining shoes at Kings Cross Station, Alfie unexpectedly sees his fathers 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. Alfie is determined to rescue his father from this strange, unnerving place ...