During the Emperor’s coastal inspection tour, Crown Prince Jianwen witnessed his mentor and friend, Admiral Zheng, suddenly assassinate the Emperor. However, Jianwen himself was falsely accused by the imperial court of patricide and usurpation of the throne. In a panic, he fled to Quanzhou aboard the Azure Dragon Spirit Vessel, intending to return to Jinling to seek help from his Uncle, the Prince of Yan. Admiral Zheng, following the order of the Prince of Yan (who was acting as regent), returned to Quanzhou to arrest Jianwen. After seeing through the plot, Crown Prince Jianwen embarked on a southward escape from Quanzhou. Along his journey, he befriended Shichiri, a ninja from Japan; Tengges, the commander of the Mongol naval forces; and Harold, a Portuguese naturalist. The four forged a sincere friendship during their adventures and planned to head toward the largest pirate base of Pojun on Penglai Island in the South China Sea—using this escape as a chance to investigate the truth behind Admiral Zheng’s assassination of the Emperor. At this time, various forces both inside and outside the imperial court were beginning to stir.