A police station and a fire station adjoining each other cooperate in combating crime and fire in the most brutal and tragic cases.

On his first day, Detective Jin Ho-gae works jointly with firefighters to resolve a kidnapping case.

Code ZERO

The first responders try to stop a suicide attempt, but the case turns out to be more complicated.

Code TWO

Ho-gae's house is said to be haunted. He and Do-jin try to solve the mystery that lies in the ashes.

Code YELLOW

A driver is arrested after a hit-and-run accident of a child. A shocking truth awaits.

Code V30

Ho-gae starts an undercover operation. He must stop a crisis that may result in mass casualties.

Code BLACK

An unidentified body is found at the scene of a fire. An unlikely person is held as a suspect.

Code RED

Ho-gae identifies a new suspect, while the case becomes evermore ensnared in mystery.

Code BLUE

Ho-gae reinvestigates a murder case and gets help from Song Seol and Yoon Hong.

Code CLEAR

Firefighters rush to save a teenage girl attempting suicide. Police find a body of a newborn baby.

Code PINK

The first responders search for the father of the stillborn child. They then meet a strange patient.

Code AMBER

Ho-gae misses Hyun-seo by a second. He and Seol pursue the evasive kidnapper.

Code ONE

A series of fire incidents occur. Do-jin suspects a chain arson and goes to see Ho-gae.

Code F63.1

A bound corpse emerges following a serial arson. The first responders to unite in the investigation.

Code ORANGE

Two fires break out in different locations. The first responders find themselves in a crisis.

Code B

The first responders and the NFS cooperate to uncover clues to the serial arsonist.

Code R98

The arsonist's final plan gets revealed. Can Ho-gae save everyone from danger and catch the criminal?

Code GREY

When a murder occurs at Myeong-pil's villa, Ho-gae leaves his post and joins the case. Kang Do-ha joins the National Forensic Service.

Rapport Building

Do-ha concludes that the death at the villa was an accident, but Ho-gae continues his investigation. Do-ha uncovers the dark side of the neighbours.

Salami Tactics

An unidentified body is found after a brawl at a junkyard. A crisis arises during the autopsy.

Hot Zone

Criminals plan to endanger the NFS building. Can the team safeguard the place?

Code GREEN

The police and fire department respond to an urgent call about a horrifying incident regarding organ extractions.

Code PURPLE

Ho-gae delves into the investigation of Ma Joong-do's murder and reopens a past murder case and prison escape.

Trust Fall

Ho-gae vanishes after a caravan explosion. Amidst the chaos, a showdown is drawing near.

Overkill

Supported by the NFS, the first responders confront the sinister mastermind in a decisive showdown.

The First Responders

Episode · Musim 1