Korea, 1645 - Joseon Dynasty: a partially blind and gifted acupuncturist, Gyeong-su, is invited to work alongside the royal physician in the palace of King Injo, just before the crown prince Sohyeon returns after having been held captive by the Qing Dynasty. Prince Sohyeon and his father begin to differ in opinion on the future direction of their dynasty, leading King Injo to suffer from severe anxiety and paranoia. One night, Gyeong-su witnesses prince Sohyeon's death. Disbelieved as a witness on account of his blindness, Gyeong-su must struggle to reveal the truth while not falling prey to the power-hungry conspirators of the palace.

Ryu Jun-yeol
as Cheon Gyeong-su

Yoo Hai-jin
as King Injo

Choi Moo-seong
as Lee Hyeong-ik

Cho Seong-ha
as Lord Choi

Park Myung-hoon
as Man-sik

Kim Sung-cheol
as Crown Prince Sohyeon

Ahn Eun-jin
as Consort Jo

Jo Yoon-seo
as Crown Princess Kang

Lee Joo-won
as Seok-cheol

Kim Yae-eun
as Court Lady Seo