Mun-ju resigns as an ambassador to support presidential candidate Jun-ik; but when they attend a mass for peaceful reunification, a sudden gunshot rings out; amid the turmoil, a mysterious man named San-ho saves her and vanishes.

As Mun-ju continues her investigation, Jun-ik’s family tries to intervene. Determined to get to the bottom of it all, Mun-ju declares her intent to run for President. Meanwhile, staff in the White House grow concerned over an intelligence briefing, and one of them takes measures into their own hands.

With Ok-seon's backing, Mun-ju quickly rises as a leading presidential candidate, but on her way to declare her candidacy at Gwanghwamun Square, an unexpected crisis strikes, and San-ho rushes in to save her.

Mun-ju finds herself conflicted over the mysterious mercenary. Meanwhile, Chang-hee makes a discovery that will threaten national security.

As signs come true, Mun-ju makes a last-ditch attempt to warn the country about its steady march to war; the survival of the country is uncertain.

Mun-ju and San-ho grow closer, but a surprise leak threatens it all; as San-ho tries to get to the bottom of the leak, Mun-ju receives some intelligence that changes everything.

Mun-ju pursues the secret behind the submarine and Jun-ik's vast estate, edging closer to the heart of the conspiracy; she chooses to accept a dangerous invitation and confronts it head-on.

As the threat of war resurfaces, Mun-ju heads into enemy territory to bring an end to it all with San-ho following close behind.

The mastermind behind everything finally reveals their cards, but can San-ho do what’s needed to stop the outbreak of a global conflict?