A few years after the battle of Rochester (Ironclad - 2011), an unnamed generic castle along the border of England – Scotland which has been occupied by English nobleman Gilbert de Vesci has to struggle with attack from local Celts. Gilbert, on his deathbed, asks his young son Hubert to seek for his cousin Guy de Lusignan to help them protect the castle. Hubert starts his journey and comes back together with Guy who asks him to pay for his help as a mercenary, Berenger – Guy’s battle hardened friend , Mary – a serial murder and Pierrepoint – an executioner, four of them then become Hubert’s workhorses in the battle against Celtic raiders.