More than 100,000 people gather by the Mekong River in North-East Thailand on November Full Moon every year. After sunset, mysterious fireballs rise up from the river and disappear into the sky. Where do the fireballs come from? While the locals still adhere to the traditional myth that they are the dragon, Great Naga, making a sacred offering to Buddha, the Western visitors take a more sceptical stance: Dr. Norati sets out to prove that the fireballs are natural while Dr. Surapol wants to prove the phenomenon a hoax. Meanwhile, temple-custodian Abbot Loh believes his monks have been responsible for the "miracle" for the past 30 years.