Eight hundred years ago, King Singha Worraman created the Katha Singha, a divine mace, and gave it to General Chaiya to protect the Tai kingdom. A deadly conflict with the Royal Priest led to Chaiya's death, and the priest’s daughter, Buasawan, shattered the mace before dying.

In the present, Trai, raised by a monk, travels to Singhanakhon to uncover his past. There, he meets Sarinda, who can read the ancient Trai language. Together, they face her father Suttha, who is corrupted by dark magic and seeks the broken mace to save himself—sparking the final clash of an age-old war.