As King Go Nam-mu is out on the battlefield during Goguryeo's war against Han Dynasty, Queen Woo Hui and Prime Minister Eul Pa-so occupy the palace in his absence. However, many begin to covet the royal power, and conspiracies among them begin to emerge. The conflict escalates as the King does not yet have an heir to the throne.

Upon returning from battle, King Go Nam-mu is poisoned and dies. The rumor of this unexpected event soon spreads, and those who seek power conspire. Meanwhile, Queen Woo Hui must protect herself without the King. So with the help of Mu Gol, she flees to meet the Third Prince.

As instructed, Queen Woo Hui visits the Third Prince to initiate the levirate marriage. However, upon seeing the consequences of his heinous actions, she concludes that the Third Prince is unworthy of any claim to power. Realizing the urgency, she escapes to avoid further complications. Meanwhile, those who have been biding their time sense that the moment has come to reclaim the throne they believe is rightfully theirs.

Word of the king's death travels in the ears of Yeon Bi of Jolbon. His passing gives rise to her ambitions of being the next queen. She travels fast to make the first move. Meanwhile, Queen Woo seeks refuge as groups of assassins close in on her.

Eul Pa-so continues to list potential suspects who might be responsible for His Majesty's death, ultimately concluding that the spy must be someone who knows of the king's demise. Meanwhile, the White Tigers draw closer to Queen Woo, coming within an arm's length of capturing her.

Queen Woo is confronted with a life-or-death choice that will shape the destiny of her entire family clan, all while being relentlessly pursued by White Tigers. In the heat of this peril, she senses that someone within her circle is covertly leaking her whereabouts. At the same time, Eul Pa-so waits in the shadows, ready to act on the moves he expects her to make.

While preparing to leave, the Queen kills the Head Maid after finding out that the Head Maid betrayed her. Believing that Eul Pal-so will come and help them with returning to the palace, the Queen takes the risk and goes to the ferry dock despite being chased by the White Tigers. Meanwhile, the Queen decides to make the Fourth Prince the new king through a levirate marriage.

Bal-gi, Pae-eui, and their soldiers advance to start a war against Queen Woo. Recollecting how he was punished by Nam-mu for desiring the throne, Pae-eui reestablishes his determination to claim the throne. Although the oath of allegiance the five tribes made to King Chumo has been broken, Queen Woo still chooses to defend her palace. Then, reinforcements arrive to join hands with Queen Woo.