A heroic doctor steps in to help a distraught boy. Intern Gang Dong-ju helps Dr. Yun Seo-jeong with emergencies at Geosan University Medical Center.

Dong-ju wonders whether hard work is enough to get ahead. Doldam Hospital gets a new doctor in general surgery. Seo-jeong sees a face from the past.

Dong-ju questions Teacher Kim's ways, despite his awe-inspiring skills. Seo-jeong must deal with the ramifications of her actions.

Being principled may be relative. It's all hands on deck after a major highway accident. Dong-ju tries to find out more about Teacher Kim's identity.

Teacher Kim makes demands of his own. Myeong-sim shows the staff how it's done. Associates from Seoul stop by Doldam. In-beom makes a gut call.

When Doldam gets a surprise, everyone tries to cope. Dong-ju wants to know where he stands. Teacher Kim gets what he wants -- for now.

A patient comes first -- no matter what. Seo-jeong gets an unexpected pep talk. Teacher Kim's compassion proves to be multilayered.

Dong-ju makes a call -- to Chairman Shin. Teacher Kim reminds Yun-wan of the importance of basics. Seo-jeong vexes an old mentor. It's Friday at Doldam.

The inspector from Geosan tries to stop the Doldam staff from treating patients. But there's a multicar accident -- and a drunk driver at the scene.

Yun-wan wants to know if Dong-ju is on his side. A soldier goes missing. Seo-jeong doesn't back down, but Teacher Kim shows her how it's truly done.

Dong-ju gets bad advice and faces the consequences. Seo-jeong gets put on the spot. Yun-wan dials up the pressure but Teacher Kim pushes back.

The staff starts preparing for Chairman Shin's surgery and Seo-jeong gets her big chance. Doldam may have an epidemic on its hands.

Seo-jeong volunteers to deal with a critical patient. Doldam averts a crisis. Dong-ju shows his appreciation. Teacher Kim catches In-beom's mistake.

In a twisted world that demands blind obedience to its rules, there's no room for those with integrity and ability. Shin's surgery gets complicated.

Teacher Kim plans to do the impossible, and Yun-wan will do anything to stop him. In-beom wants to do the surgery -- for the team, not his father.

A large audience waits outside the operating room -- and not everyone wants the team to prevail. A shifty reporter starts lurking around Doldam.

It's only after time passes that seemingly minor moments in life start taking on greater meaning. Yun-wan gets his way -- and orders Doldam's closure.

Yun-wan makes sure that old wounds don't lie dormant. The furtive reporter keeps snooping around. Dong-ju confronts Teacher Kim about the past.

Teacher Kim takes the staff to Seoul. Yun-wan won't let his old rival have the spotlight. Bu Yong-ju is hurt but stands by romance and his principles.

During his trip to the main hospital, Teacher Kim leaves an impression — especially on three young doctors who find themselves in his hospital lobby.

Teacher Kim shocks Seo U-jin with his unconventional approach to saving a high-ranking official, and bans Cha Eun-jae from assisting his surgeries.

Do Yun-wan creates chaos by bringing his own team of doctors. U-jin's participation in Park Min-guk's surgery sparks a misunderstanding.

U-jin gets caught in the middle of two feuding teams of doctors when the family of a patient threatens to sue for malpractice.

New doctors get a taste of their first Friday at Doldam Hospital. U-jin refuses to treat a patient who triggers his childhood trauma.

Teacher Kim leads his team in saving two critical patients at the same time. Eun-jae steps in to protect a woman from her abusive husband.

Min-guk becomes determined to turn people away from Teacher Kim. A situation Eun-jae tries to mitigate takes a turn for the worse.

Even in her final moments, a paramedic helps save another's life. U-jin shows Eun-jae his way of resetting the mind from worries.

U-jin looks into diagnoses for Teacher Kim's arm pain. A bus accident conjures up a regretful moment that haunts Min-guk's conscience.

Yoon A-reum protects a patient's rape kit from falling into wrong hands. Min-guk finally brings up the bus accident from 11 years ago to Teacher Kim.

Min-guk asserts his authority by restructuring the hospital staff. U-jin is stunned to learn which surgeon was behind a faulty operation.

A recruiter with bitter resentment for U-jin tries to tempt staff members to leave Doldam Hospital. Eunjae's mom asks for a favor.

Eun-jae panics when she runs out of medication from Teacher Kim before surgery. U-jin gets coerced into leaving Doldam Hospital.

Teacher Kim tasks U-jin with a final assignment. Min-guk performs surgery on a VIP patient despite pushback from Shim Hye-jin.

Do In-beom returns to Doldam Hospital to investigate an unsuccessful surgery. Min-guk decides between his greed and the truth.

Bae Mun-jeong comes clean to U-jin about the connection between their families. Teacher Kim secures a safe future for Doldam Hospital.

The medical staff of Doldam Hospital fly out in a helicopter to a ship lost out at sea on behalf of Teacher Kim, who is absent on vacation.

As the patient's lung condition deteriorates due to tuberculosis, Teacher Kim opens the trauma centre operating room for Ri Bok-young's surgery.

Doldam Hospital hires new personnel. The people of Doldam, who thought Teacher Kim would be the new head of the trauma centre, hold an emergency meeting.

Patients injured in a residential fire are rushed into the emergency room. Seo U-jin treats the suspected arsonist despite Jang Dong-hwa's criticism.

Cha Jin-man hates that Teacher Kim's methods are deeply rooted into Doldam Hospital and takes everyone except Lee Seon-ung and Dong-hwa to the trauma centre.

The trauma centre loses a patient and receives another patient in critical condition. Meanwhile, a child visits Teacher Kim at Doldam Hospital.

Wounded soldiers are rushed to Doldam Hospital. A-reum is left alone to tend to the emergency room when rogue patients suddenly cause a scene.

Patients rush into the emergency room while the staff tends to surgeries. Doldam Hospital falls into chaos as the gunman's identity is revealed.

When an old building collapses resulting in several casualties, a disaster medical support team is dispatched to the site.

Doldam Hospital receives news of a second collapse, but the place is still full of injured people. Teacher Kim leaves everything and heads to the scene.

Go Gyeong-suk does not give up the legal battle over her son's death. She proposes a secret deal to bring down Jin-man, but Teacher Kim opposes to it.

Jin-man fails to find the culprit who broke into the director's office. His reputation is further ruined as incidents from his past become known.

Gang Dong-ju returns to Doldam Hospital, with his unconventional proposals causing a stir in the trauma centre.

Eun-jae performs emergency surgery on a non-trauma patient while she must join another surgery for a patient with multiple traumas.

People injured from a forest fire rush into Doldam Hospital. Yet, the trauma centre is empty due to the staff staging a boycott against Dong-ju.

A fire approaches as if it would devour Doldam Hospital at any moment. Only after evacuating all the patients do the staff realise Teacher Kim was gone.