He guides Kang Dong-joo (Yoo Yeon-seok) and Yoon Seo-jeong (Seo Hyun-jin), both who were transferred from Geogan University Hospital a 5 years apart, to become great doctors by teaching them to fight against power and money for the sake of patients.

In the meantime, Cha Eun-jae (Lee Sung-kyung) is suspended after making another mistake in the operation room and has no other choice but to follow the two doctors to Doldam Hospital.

Three years following the events of the second season, the Doldam Hospital Regional Trauma Center which was Kim Sa-bu's long-held dream will be opened.

First script reading took place September 13, 2016, at SBS Ilsan Production Studios in Goyang, Gyeonggi Province, South Korea.

[28] The first script reading took place in September 2019 at SBS Ilsan Production Studios in Goyang, Gyeonggi Province, South Korea.

[30] In September 2021, it was reported that production for Season 3 would begin in late 2021, but filming had to be postponed due to the actor's schedule and the outbreak of the COVID-19 virus.