A man woke up with amnesia to find that he had bested five swordsmen and that he carried a strange object. Saved from his grave injury by a healer of unique abilities and remarkable beauty, they learn that others of power and station are willing to kill for the object he carries. On the road to rescue his ransomed family, whom he does not remember, Imar's attraction to Dalla grows and he learns that the eight sided object in his pouch is a key to a faraway underground fortress containing advanced knowledge and technology from the forgotten past. Others would have the Octagon Key because it also unlocks access to powerful weapons unimaginable in this Medieval Age of Sail. Imar must find the self he cannot remember, keep the key from falling in the hands of evil, and decide whether to destroy the Octagon Key or use it for good.