Heo Im, who is born in a concubine family in Joseon era and has very outstanding medical skill, is frustrated about his career as he fails to climb to higher positions in the government because of his background. By accident, he travels through time to modern Seoul 400 years later and meets modern doctor Yeon-gyeong. Thinking that Heo Im is weird, she hopes to get rid of Heo Im but instead, they travel back to Joseon together again.