Han Yunxi meets a stranger while searching for a rare herb in the mountains. She takes something that belongs to him and escapes to a mysterious valley.

Suspicious of Long Feiye's return, the Empress Dowager decides to plant a spy. Meanwhile, a royal decree surprises Yunxi and her family.

The Empress Dowager asks Yunxi to work for her in exchange for her mother's whereabouts. Plans are made to attack Feiye on his wedding day.

Yunxi stops the poison from spreading through Feiye's body as he lays unconscious. She uses the opportunity to examine him for the secret mark.

Yunxi has little time to get closer to Feiye and complete the undercover mission. Meanwhile, Feiye grows suspicious of her and keeps his distance.

Gu Qishao's confession gains the Crown Prince's trust. Chu Qingge wins the Emperor's favor with extravagant gifts. Feiye examines a series of deaths.

Yunxi heads to the morgue to study the victims. When she comes home, Feiye is waiting for her, fully aware of who she is and what she's been doing.

Tang Li chases after a woman who he believes is the culprit to the murders. Tagging along behind him, Yunxi and Feiye enter her hideout.

To everyone's surprise, Feiye takes care of Yunxi all night. Though unconvinced of Qingge's sincerity, the Empress Dowager publicly praises her.

Yunxi challenges a case at the Grand Court. Feiye tests Yunxi's allegiance by asking her to help him bathe.

Feiye takes Yunxi to a prisoner who's been poisoned. Qishao asks what Yunxi's been up to. Feiye spots the two together and begins to feel jealous.

Long Changbing has Yunxi arrested and thrown in a prison cell. When Feiye hears Yunxi may be in danger, he rushes off to save her.

Seeking revenge, Feiye brings a witness before the Emperor to testify. The Crown Prince's uncle is dealt a severe punishment.

When Changbing calls on her to help with face rashes, Yunxi turns the request into an opportunity to find more information about her mother.

Yunxi prepares for an unpleasant visit back home to her family. There, Feiye is shocked to see a portrait of a woman he knows.

The arrival of a general's daughter, who seems close with Feiye, bothers Yunxi. Wanting to get away, Yunxi heads to Qishao's valley.

Much to Feiye's dismay, Yunxi returns to her residence drunk and with Qishao. Qingge realizes she's not safe when she sees a worrisome message.

Feiye abruptly distances himself and hides his condition from Yunxi, who's hurt when he stands her up at the festival.

Convinced Baili Mingxiang is poisoning Feiye, Yunxi takes matters into her own hands by feeding him dessert laced with medicine.

The Empress Dowager tells Yunxi more about her mother. In the midst of sabotaging the Emperor's plans, Feiye falls unexpectedly weak.

After learning the truth about Feiye's condition, Yunxi asks Qishao about a curious poison. Consort Yi accuses Yunxi of being a spy.

Qishao shares his suspicions about Feiye with the Crown Prince. The Empress Dowager turns her attention to Consort Xiao's schemes.

If Yunxi wants to see her mother, she must follow the Empress Dowager's orders. At a birthday celebration, the Emperor is attacked.

Feiye decides the best way to protect Yunxi is to push her away. The Emperor catches wind of the Crown Prince's secret research project.

Yunxi's misunderstandings about Mingxiang and Feiye dissolve. While she works on a cure for the poison master, Feiye makes his way to her in the valley.

Conflict brews between the Crown Prince and Prince Long Tianqing. Meanwhile, back in her residence, Yunxi makes medicine for Mingxiang.

The poison master grows keen to uncover Yunxi's identity. The Empress Dowager finds that her threats no longer work on Yunxi.

In response to rejection, Mingxiang acts out. Consort Yi figures out that Feiye's been keeping something startling from her.

Qingge's plot to harm the Crown Prince puts the wrong person in trouble with the Emperor. When Yunxi is poisoned, Qishao takes care of her.

Despite Yunxi's strained relationship with her father, she wishes to save him. The Empress Dowager sees a chance to get rid of Feiye for good.

Setting out with Yunxi and the others to locate the poison master, Feiye comes up with a plan to deter those who might try to stop them.

Separated from Feiye, Yunxi follows a beast through the cave. Gu Beiyue reveals the surprising connection between her and the poison master.

The Emperor locks up Prince Long Tianqing, who's later visited by the Crown Prince. Yunxi's father is freed and returned to his family.

Yunxi alerts Feiye of Qingge's sinister intentions. Later, Qishao opens up to Yunxi about his mother and his difficult past.

The Crown Prince refuses to believe that Qingge would betray him. The poison master resolves to help Yunxi obtain a cure for Feiye.

Feiye arrives too late to prevent Mingxiang from committing a terrible deed. Meanwhile, a deadly plague threatens the kingdom.

Questioning locals in an affected village, Yunxi realizes the plague may not be a disease, but a poison. Feiye worries about her safety.

After discovering a poisoned well to be the root cause of the so-called plague, Qishao travels in search of an ingredient needed for the cure.

Displeased with news of Feiye's success, the Emperor has Consort Yi kidnapped. A threatened Crown Prince makes a move against his father.

As chaos and tragedy break loose at the palace, Feiye and his forces take over. The Emperor demands answers from the Crown Prince.

Yunxi finishes up a cure for Mingxiang. Elsewhere, Qingge and the Emperor take advantage of Mingxiang's rage and jealousy.

Yunxi has a heart-to-heart with Qishao, and confronts Feiye after learning the truth about the circumstances surrounding the poison master's death.

Though Mingxiang successfully entraps Yunxi, she soon loses control over the situation. Feiye and his men hurry to reach them.

Determined to save Feiye, Yunxi comes to a painful decision. After receiving news from home, Qingge has a tough choice of her own to make.

Shocked to find that his soup has been poisoned, the Emperor orders an investigation. Qishao informs Feiye of Yunxi's plans.

Qishao protects Yunxi from a pair of malicious attackers. The Emperor is upset to find out who has been trying to poison him.

Appalled by the Emperor's army of poisoned soldiers, General Mu makes an alliance with Feiye. Yunxi finally comes across what she's been looking for.

Yunxi asks for Qishao's help one last time. Feiye and his allies ready themselves for a gruesome battle against the Emperor.