During the reign of Emperor Shizu of the Yuan Dynasty, Marco Polo traveled to the capital of the Yuan Dynasty. His maid {Lin Wan} unexpectedly discovered that the layout of the city walls and palace regulations of this imperial capital actually concealed the Eight Diagrams codes of the "Luo Shu". These codes are not only defensive weapons, but also point to the secret room containing the imperial seal. The powerful minister Ahema coveted the jade seal and wanted to control the government, so he pursued the two men. Lin Wan relied on his Chinese-Mongolian bilingualism and code-deciphering ability to take Marco Polo through the streets, temples and palaces of the Yuan Dynasty. From the cryptic symbols in the Pagoda of Baita Temple to the mysterious codes at Jishuitan Pier, they decoded step by step and were startled step by step, and finally found the secret room under the dragon chair in the palace. Faced with Ahema's coercion and inducement, Lin Wan stuck to his heart and returned the jade seal to Kublai Khan, safeguarding the stability of the Yuan Dynasty's regime.
