Risking lawsuits to save lives, surgeon Lee Hae-seong has clashes with the hospital director, Park Geon.

A sudden explosion creates numerous casualties when a crane topples over. Hae-seong, Ttol-mi, and Ji-na all happen to be at the accident scene.

A magnitude 6.5 earthquake strikes the city of Seoul, and Hae-seong and Ttol-mi try to treat the injured.

People are still alive and trapped under a massive pile of concrete. With patients waiting, Hae-seong must make a difficult decision.

Doctors at Mirae Hospital perform triage on the victims, but Director Park and Han U-jin decide on a different plan.

Despite emergency measures, Mirae Hospital is running out of electricity and Director Park readies for a complete shutdown.