Season 1

On March 2, the President of South Korea is attacked in a marketplace. Han Tae Kyung, an agent who did not prevent the attack, learns that the President will be assassinated in three days' time.

Tae Kyung is immediately suspected for being an accomplice in the president's assassination, but he figures out the truth more quickly than anticipated, putting him in immediate grave danger.

With Bo Won's help Tae Kyung discovers more clues about his father's death and how it's connected to the president's assassination. Cha Young believes that the Chief of Secret Service is involved.

Tae Kyung and Bo Won are closer to locating the president when the Special Prosecutor drops a huge bomb on the President's reputation.

Tae Kyung manages to save the president, but at a high cost.

The Blue House reveals the news of the assassination attempt to distract from the news of the Yangjinri attack. Tae Kyung discovers that the witnesses to the assassination attempt are getting killed off one by one.

Chief of Staff Shin Gyu Jin gets involved too deep when he tries to resolve the president's scandal.

Tae Kyung's faith in the president wavers, but Bo Won's demand for truth and justice inspire him to locate the last witness involved in the Yangjinri incident.

Tae Kyung is framed for another murder, and he will stop at nothing to make sure Kim Do Jin cannot go through with his plans for another disaster.

Lee Cha Young's loyalties are in question as Tae Kyung and the President try to find solid evidence of Kim Do Jin's evil plans.

With Lee Cha Young's help, Tae Kyung discovers what Kim Do Jin is going to do to bring North and South Korea at the brink of war again.

Tae Kyung must foil a terrorist act that threatens to kill thousands and destroy the center of Seoul.

Knowing that more agents' lives are at stake, President Lee decides to face Kim Do Jin head on, even if it means walking to his own death.

President Lee decides to resign, but Do Jin still has men on the inside who will make sure the president will not live to see another day.

The corrupted officials and henchmen who have been working for Kim Do Jin are rounded up. President Lee goes missing once again, but unearths Chairman Kim's disastrous plan for Yangjinri.

The race is on to find the other three bombs before there are more casualties.