[Edaily Reporter YUN GI BACK ] An intern with a bright smile threatened a patient’s life. In a plot twist, Kim Woo-seok’s character on “Doctor X” attempted to suffocate Jeon Guk-hwan with a pillow, ramping up the drama’s tension. Combined with the reactions of Lee Jin-hee, who merely watched, and Kim Ji-won, who rushed to stop him, curiosity mounted about the past of these four characters.

At the end of the 10th episode of the SBS Friday-Saturday drama “Doctor X: The Age of the White Mafia,” which aired on the 7th, Kim Seung-hyo (played by Jeon Guk-hwan), the founder of the medical volunteer organization “White Wings,” made an appearance. As the leader of the organization where Gye Su-jeong (played by Kim Ji-won) had once worked, he was a respected figure who carried out humanitarian medical activities in third-world countries.
Kim Seung-hyo, who visited Gu Seo-dae Hospital to undergo a heart transplant, designated Jo Won-jin (played by Lee Jin-hee) as his guardian and Gye Su-jeong as his surgeon. His appearance left Gye Su-jeong, Jo Won-jin, and Park Tae-kyung (played by Kim Woo-seok) all in shock.
Park Tae-kyung then suddenly pressed a pillow over Kim Seung-hyo’s face while he was asleep. This was a side of him completely different from the cheerful persona he had previously displayed as the “Sunshine Intern.” Jo Won-jin’s failure to stop him only deepened the mystery. Just as Gye Su-jeong, who had entered late, stepped in to block Park Tae-kyung, Kim Seung-hyo opened his eyes and greeted him with, “It’s been a long time, Doctor X,” bringing the episode to a close.
This scene stood in stark contrast to the day’s earlier developments, where doctors had joined forces to save a life. Park Tae-kyung’s hostility toward the founder of a respected medical volunteer organization, Jo Won-jin’s silence, and Gye Su-jeong’s reaction all hinted at a hidden story behind them. With only two episodes left until the series finale, Gye Su-jeong’s past has emerged as a key plot point.
Earlier, the medical team had successfully performed a highly complex surgery on Lee Hyun-ah (played by Lee Chae-yu), an 8-year-old pediatric cancer patient. The procedure involved removing six organs from her body to excise the tumor and then reimplanting them. Although Gye Su-jeong and Jang Hee-sook (played by Lee Jung-eun) led the effort, they struggled due to a shortage of staff.
A breakthrough came when Bu Seung-kwon (played by Son Hyun-joo) and Bae Heung-gon (played by Lee Sung-wook), who had been attending a residents’ protest meeting, left the polling station to join the surgery. Despite pressure from the Mokryeon Association to halt the procedure, Bu Seung-kwon declared that he would continue the surgery using his authority as hospital director. With Kim Seong-jin (played by Heo Jun-seok) joining the effort as well, eight doctors—ranging from the hospital director to interns—saved the child’s life.
After the surgery, the Mokryeon Association pushed for disciplinary action against the medical staff and the termination of Gye Su-jeong’s contract, but the disciplinary measures were put on hold when Hyun-ah’s mother threatened to file a lawsuit holding the hospital and the foundation accountable.
According to Nielsen Korea, this episode recorded a nationwide viewership rating of 17.7% and a peak rating of 20.2% in the Seoul metropolitan area. The 2049 demographic averaged 7.2% with a peak of 8%.
“Doctor X” airs every Friday and Saturday at 9:50 p.m.