Moments from death a young man is rescued by a renowned warrior. Realizing unsurpassed physical potential in the young boy he trains him into the most dangerous man alive. As he becomes a young man he goes on a lone mission of vengeance against the vicious slave traders who enslaved him as a youth and the treacherous warlord who killed his father.

Continuing from Ong Bak 2's 1440s, Prince Tien fails to revenge his parents' murder by the evil new ruler. The beaten Tien is rescued. Can he bring peace to the kingdom?