It is 480 BCE and the mighty Persian Empire, continuing its long march of conquest, strikes westward into the free city-states of Greece. Led by the capricious despot Xerxes the Great, its irresistible army seeks to overcome a different kind of foe that awaits them in the waters off Artemisium in Northern Greece. Onboard a Greek trireme, a young Athenian marine holds fast to his certainties of love and honor and the memory of his father. In the maelstrom that follows, the search for truth and purpose, unfolds mysteries, ensnares a king, and frees a people.