The Legend of the Mekong River

Petai, an archeologist, and Songpob, a canny antique trader examine an engraved stone from Khong river bank and discover that it is actually a gate to the ancient Nakusa city under the throne of the powerful Four Nagas. Ratchasee and Frank, antique collectors, also learn about this secret and they wish to possess the superpower of Nagas from Nakusa city. They know all along that a trove of precious treasures is hidden there.