Set right before the fall of Thailand's old capital, Ayuttaya, Bang Rajan draws on the legend of a village of fighters who bravely fended off the Burmese armies. With no support from the Royal army, the villagers drives the invading Burmese away many times until their names have become legendary during the time. As each subsequent battles becomes fiercer, the villagers tries to forge a canon to battle the enemy in a final battle where everyone, women and children included, die in combat.

Tai, a young man arrested on a crime charge, is discharged thanks to his twin brother Tan's dogged help. After being set free, he finds Tan in a coma with severe injuries. Tan's girlfriend, Pang, tells Tai that his brother got involved in some risky business to raise money to fight Tai's case. Tai feels guilty that his problems brought his brother trouble. He then traces what happened to Tan, which ultimately leads him into illegal basketball gambling. Tai wants to find out who is behind this gambling and why his brother was beaten unconscious. He finally joins the "Fireball" team, a team which belongs to Hia Den and whose players include Singha, Kay, Ik, and Muek. In order to uncover the truth, Tai trades many things-possibly even his life.