In the winter of 1794 Bow Street Runner and amateur pugilist Dan Foster is assigned to guard a Royal Mail coach. The mission ends in tragedy when a young constable is shot dead by a highwayman calling himself Colonel Pepper. Dan is determined to bring Pepper to justice, but the trail runs cold. Four months later Dan is sent to Staffordshire to recover a recently excavated hoard of Roman gold which has gone missing. Here he unexpectedly encounters Colonel Pepper again. The hunt is back on, and this time Dan will risk his life to bring down Pepper and his gang.