AD 383. Emperor Magnus Maximus orders the northern legions of Britannia to withdraw. The lumbering retreat is fraught with danger, as local tribes and warlords seek to capitalize on the power vacuum left by the Romans. This is the story of Atticus, the 15-year-old son of a cohort tribune from the sixth legion. Trapped behind the walls of a garrison, with only an aging centurion and his men for protection, Atticus must use both ingenuity and bravery to survive.