In South Korea, there are cases that neither the police, the military, nor the National Intelligence Service can easily touch. Despite the existence of national laws and systems, crimes that slip through the cracks and threaten the lives of citizens never cease. Terrorism with hundreds of hostages, armed criminal organizations crossing borders, serial killings, and large-scale explosive incidents. The moment threats that cannot be stopped by ordinary investigations and procedures become reality, the government makes its final choice. An organization unknown to the world, the Special National Enforcement (SNE). They are South Korea's final response agency, deployed only to scenes where failure is not an option.

The very existence of the Special National Enforcement is a secret. The media does not know their name, and the citizens do not know their faces. When a case ends, all credit goes to the police and related agencies, and they disappear without a trace as if nothing had happened. But someone knows. That there are people who remain at the scene until the end, when everyone else has given up, to protect the citizens.

At the center of it all is a single Special Enforcement Officer.

Guest.

A former member of the 707th Special Mission Group of the Army Special Warfare Command and a founding member of the Special National Enforcement. A field commander who survived numerous actual battles and saved more lives than anyone else. He is not a man who ignores the law. However, in the face of a crisis where the lives of countless citizens are at stake, he knew better than anyone that endless procedures and debates over responsibility would not save lives. That is why Han Tae-seong, the Director of National Security, always left the same words.

"I'll take responsibility for the procedures. You just protect the people."

Those words were the trust given to Guest, and a responsibility that no one else could replace.

Special Enforcement Team 1 was composed of South Korea's top experts. Lee Su-hyeon, a sniper who never misses a target even from kilometers away; Jeong Do-yun, an EOD expert where not a single mistake is permitted; Kang Ji-hyeok, an intelligence analyst who connects all information from unseen places; and Oh Se-rin, a tactical medic who saves lives even in the midst of flying bullets. Though experts in different fields, they moved as one team in the field. To them, trust was more important than rank, and the promise to ensure each other's survival was stronger than any command.

However, as time passed, the incidents became increasingly sophisticated. Terrorism, murder, kidnapping, and arms trafficking, which seemed unrelated, were connected like a single thread somewhere, and someone was preparing a massive plan with the entire Republic of Korea as the stage. Crime was no longer just for money or revenge. A grand intention to shake the nation and collapse society was moving like a shadow.

The person performing these missions was none other than Special Enforcement Officer Guest.

A peaceful morning at the office of Special Enforcement Team 1 of the Special National Enforcement (SNE)