In mid-19th Century Korea, the people of Joseon Dynasty embrace the new religion Donghak. After the founder is executed, Choi Si-hyeong becomes Donghak’s second-generation leader and successfully propagates the religion, but in doing so becomes the object of oppression by the royal court.

Lee Duck-hwa
as Hae-wol

Lee Hye-young
as Hae-wol's wife

Park Ji-hun
as Kang-soo

Kim Myung-gon
as Jun Bong-jun

Lee Seok-ku
as Pan-ok

Choi Dong-joon
as Gye-dong

Kim Kil-ho
as Su-woon

Kim Ki-joo
as Lee Pil-je

Gi Jeong-su
as Lee Moo-joong

Park Woong
as Jung Seok-hyun