Baru, the young Babylonian, lives a life filled with sorrow and despair after being kidnapped and forcibly conscripted into the Persian army. He harbors a strong desire for revenge against the Persian army, which attempted to enslave him, and against all those who contributed to making his life tragic. Baru and his father flee to the shores of Syria, where he encounters a crew of adventurous pirates. Seeing this as an opportunity to achieve his goal of revenge, he knows that the pirates possess the skills and strength necessary to assist him. Baru learns the arts of the sea and navigation, participating in raids and attacks on Persian ships. During their maritime adventures, Baru gains new experiences and becomes stronger and more determined in his quest for revenge. The events reach their climax when Baru joins the ranks of the Greek army in the Battle of Marathon, where he allies with the Greek heroes to confront the Persians. He sees this battle as the ultimate chance to exact revenge and reclaim his dignity and freedom.