The Unified Silla Dynasty is when three kingdoms (Goguryeo, Baekje, and Silla) have come together after a great war and peace is ostensibly in the air, but with signs of collapse lurking from within. Despite being born with a photographic memory and an extraordinary ability to see through people and what is going on between them, Seol Mi-eun is never given a chance to use her abilities since she was born a woman. However, she comes across a major turning point when her brother, who was brilliant enough to be invited to study in the Tang Dynasty, dies suddenly – Seol Ho-eun, the third oldest brother ends up becoming the oldest in the family due to the numerous deaths that have swept through the family, decides to use Mi-eun and her extraordinary abilities for the family. Following Ho-eun’s plan, Mi-eun abandons her original name and goes to study in the Tang Dynasty under the name of her deceased brother, “Ja-eun.” After surviving numerous brinks of death to reach adulthood, Seol Ja-eun finishes her studies and comes back to her hometown of Geumseong, the capital of Silla. However, do extraordinary things happen to those with extraordinary abilities? Ja-eun starts encountering strange events on her way back home. 

Ja-eun encounters a mysterious murder on the ship from the Tang Dynasty to Dangeunpo in Silla; at a mansion in Geumseong, Ja-eun uncovers the hidden truth about a war hero who is on the verge of death after an unexplained hellfire; and she also tracks down the culprit of an event that happens in the Silla Yukbu women’s weaving competition. Soon, stories of Ja-eun’s brilliance reach the king of Silla, and she is invited to a banquet hosted by the king. However, just as the banquet is in full swing, a dead body emerges lying face down on the Wolji Pond. The king declares that no one shall be allowed to return until the truth of the case is uncovered; Ho-eun urges Ja-eun to demonstrate her talents to the king’s eyes; and Ja-eun simply wants to go unnoticed – will Ja-eun be able to survive the night? 

“It was just after the sun had risen and the fog had lifted that the cold body of the trinket merchant was found.” 

The very first case encountered by Seol Ja-eun. Ja-eun, who had disguised herself as a man to take the place of her deceased brother, finishes her studies in the Tang Dynasty to get on a ship full of diplomats back to Silla. Being a time when crossing large bodies of water is dangerous, ships traveling from one country to another carry people with different stories and backgrounds. One morning, just a few days into the voyage, a man is found strangled to his death – with his wife and daughter nowhere to be found on board. As Seol Ja-eun tries to find out the truth behind the mysterious death, a strange man whose smile never fades introduces himself as Mok In-gon from Baekje and continues to interrupt her. The two eventually end up working together to investigate – what secrets could be hidden in the man’s death? 

“If we look into all deaths we disregard as being caused by hellfire, would they really be all just hellfire? 

After Seol Ja-eun returns to Geumseong with Mok In-gon as her guest, she meets Sana, a beautiful and elegant woman who seems to have had some sort of affectionate relationship with her deceased brother. Sana recalls that Ja-eun was brilliant back when she was a child, and wishes Ja-eun would use her intelligence to solve a mysterious event that has happened to her father. One day, Sana’s father is found unconscious with red writings on his palm and has not been able to wake up since then. People say it is hellfire that is punishing him for his sins, but is that the truth? To help Sana, Ja-eun heads to Sa-hyeol Mansion, a mansion that stands out even among the most luxurious mansions in Geumseong. 

“The loom was completely ruined and broken in pieces. To have this kind of tragedy happen on my turn – what should I do?”

Every summer, Geomseong hosts an epic weaving contest. The women of Seorabeol are divided into two teams and go all out to weave finer and longer cloths than their opponents. When Ja-eun’s younger sister Do-eun takes her turn at the loom, someone breaks the loom. Ja-eun sets out to find the culprit to restore her sister’s honor. Four people want to win the competition and make their way to the palace – and one of them is the culprit!

“You shall not return until you get to the bottom of this matter. As we happen to have gathered those who are said to be gifted, use your gifts to reveal the clear truth behind this matter.” 

Seol Ja-eun is invited to a banquet hosted by the king of Silla in Wolji Pond. However, there are sayings that it is not just a banquet, but a test for the king to discover new talents that he could keep by his side. Seol Ho-eun, the one responsible for giving Ja-eun a new identity and sending her off to the Tang Dynasty, asks her “not to draw too much attention, but to showcase her wits to their full extent.” However, Ja-eun has no intention of being noticed by the king. During the banquet, however, the dead body of a falconer, whose white falcon symbolizes the legitimacy of the king, rises from the pond. The king then declares that the banquet shall not end until the truth behind the falconer’s death is revealed. Will Ja-eun be able to solve the mystery without drawing too much attention to herself?