The story is set in the southeast Korean kingdom of Silla, which has been expanded by the late King Jinheung. The first 50 episodes revolve around the political and physical battles between Mishil and the Royal Family. Mishil, a powerful aristocrat, aspires to become queen. She has acquired a significant amount of power from the Royal Family by convincing the people that she is Heaven’s Maiden. She uses this influence to gain followers at court, with the ultimate goal of becoming queen, despite her humble lineage.
One opportunity arises when the wife of King Jinheung’s grandson, Jinpyeong, gives birth to twin girls. Due to a prophecy stating that the birth of twin girls would lead to the diminishing of male heirs in the royal bloodline, King Jinpyeong was forced to abandon one of the twins. However, the prophecy also foretells that the twins would contend with Mishil and achieve great things.
Mishil and her supporters plan to expose the twins to remove the current queen and pave the way for Mishil’s ascension. To prevent this, Jinpyeong sends his youngest daughter away with a palace maiden, Sohwa, albeit with profound regret. The maiden manages to escape pursuit with the help of Munno, one of the Silla’s elite warriors.
Fifteen years later, the younger twin, Deokman, grows up in the Taklaman Desert in China, living among merchants and travelers who believe she was abandoned by her father. She is raised in a simple and carefree manner, unaware of her true identity and the reason she resides so far from her homeland. Deokman is known for her wit, charm, curiosity, and loyalty, and she is not afraid to risk her life to save others.
One day, Chilsuk, one of Mishil’s men who has been searching for the younger twin for fifteen years, tracks her down. When Deokman discovers her real identity and sees her mother die in the desert, she decides to find Munno, the person who might hold the key to her true identity.
Deokman resolves to return to Silla to uncover why she was being pursued. Upon her return, she meets her older sister, Princess Cheonmyeong, and future Korean general Kim Yu-shin. Five years later, Deokman learns that she is the daughter of the king who abandoned her, and Mishil once again tries to expose her. However, Deokman’s journey is marred by tragic events, including the accidental death of Princess Cheonmyeong.
Deokman is determined to regain her status as a princess and challenges Mishil’s quest for power. As Deokman progresses in her journey, she meets Bidam, a complex character with a tragic past. Although initially perceived as childish, Bidam’s cunning and martial arts skills come to light. He is revealed to be the son of Mishil and King Jinji, abandoned by his mother when her plans shifted.
As Mishil and Bidam’s true relationship is unveiled, Bidam remains loyal to Deokman and her dream of becoming the first female ruler. His ultimate goal is to marry Deokman, making him the king. Bidam’s devotion to Deokman is motivated by his love for her and a desire to be her confidant and source of support in her challenging role.
Despite the political power he gains, Bidam’s followers, who were responsible for his mother’s death, manipulate circumstances that lead him to oppose Deokman. They stage an insurrection against her, which ultimately leads to Bidam’s tragic fate.
Deokman becomes Queen (King) after Mishil’s death and uses Bidam to balance political power. Bidam’s love for Deokman remains unwavering, even as he faces difficult choices. He makes a secret pact with Deokman, agreeing to relinquish his power and throne upon her death.
Bidam’s supporters, also loyal to Mishil, discover this pact and fear Deokman’s wrath for their role in his mother’s death. Bidam joins them, but after being betrayed by his own comrades, he ultimately returns to Deokman’s side. However, it is too late, and his fate is sealed.
Bidam’s tragic death occurs just moments away from Deokman. Before dying, he manages to whisper her name, breaking her earlier insistence that she had no name and was merely “Her Majesty.” Deokman sheds a tear for him, and Bidam’s loyalty to her remains evident.
Deokman’s affliction eventually leads to her death, and she requests to view the heavens, the land, and what lies between before the story concludes. Her path has been challenging, but she endures until the end.