401 BC. After thirty years of war, the city-states of Greece are on their knees. As they flounder, Clearchus of Sparta is commissioned to recruit an army of Greek mercenaries. Their true purpose is unclear. They know they must venture deep into the hostile heart of the Persian Empire. They know Cyrus, brother of the great Persian king, Artaxerxes, is their paymaster. But their official objective-clearing the are of rebel tribes-convinces no one...