Due to historical reasons, the naughty young man Park Hoon (Lee Jong Suk) spent his childhood, adolescence and youth in North Korea, where he met the beautiful girl Song Jae Hee (Chen Se-yeon), but fate shattered the young man's beautiful youth. In order to run towards freedom, the two separated. Park Hoon, who came to South Korea, met Mingyu Hospital by chance, and met Han Shengxi, a female anesthesiologist who looked exactly like Jae Hee. After receiving strict medical education in the north, coupled with his father's genes and talents, Park Hoon soon became an excellent surgeon in Mingyu Hospital. This young man with the label of "North Korean defector" will have a fierce collision with Shengxi, Han Jae-joon (Park Hae-jin), the chief of thoracic surgery with the purpose of revenge, Wu Xiuxian (Jiang So-ra), the daughter of the beautiful hospital chairman, and even everyone around him...