The film is set in the early Joseon Dynasty and tells the story of the Joseon Dynasty's usurpation of the throne. Kim Nae-kyung (Song Kang-ho), a descendant of a traitor, has the ability to read people's faces, but because of his humble status, he can only live in seclusion in the wilderness with his brother-in-law (Cho Jung-seok) and his son Jin-hyung (Lee Jong-suk). The proprietress of the largest brothel in Hanyang (Kim Hye-soo) came to visit Kim Nae-kyung and persuaded him to go to Hanyang to make money by reading faces, but Jin-hyung did not understand. After arriving in Hanyang, Kim Nae-kyung made careful moves, made a lot of money, and was appreciated by the loyal minister Kim Jong-seo (Baek Yoon-sik), and even gained the trust of the king. However, due to his outstanding talent, Kim Nae-kyung had to be involved in the struggle for the throne between the king's younger brother, Prince Suyang (Lee Jung-jae), and also implicated his son Jin-hyung, who had changed his name and won the first place in the imperial examination. Kim Nae-kyung decided to help Kim Jong-seo and the little king destroy Prince Suyang's conspiracy, but he could see through people's hearts but could not decide their fate. The torrent of history continues to flow.