The day the First World War broke out, Alfie Summerfield's father promised he wo
uldn't go away to fight - but he broke that promise the following day. Four year
s 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.