Xihe, the Grand General and Crown Princess of Cangwu, returns home victorious only to find her entire family massacred. After losing a duel against a masked suspect, her wood soul scatters and possesses Shen Qianye, the unawakened legitimate daughter of the Shen family. Reborn, she learns her father was framed for treason and allegedly committed suicide. Investigating the incident, she encounters the Crown Prince seizing her family estate and Prince Pei Su taking her old wedding dress. Suspecting Pei Su of mocking her past, she assists the Crown Prince but refrains from revealing her true identity as Xihe to protect him while vowing to uncover the truth.

Drugged and framed by her concubine-born sister, Shen Qianling, Shen Qianye escapes and encounters Pei Su. Desperate for her blood, Pei Su strikes a deal: he helps her survive the trap in exchange for her becoming his spiritual servant and providing him with her blood. When Shen Qianye notices a mark on Pei Su’s neck identical to the masked killer's, she suspects his involvement in her family's massacre. She intentionally provokes Qianling to trigger Pei Su’s rescue, leading her to move into his mansion. When the Crown Prince arrives to take her back at her father's request, Pei Su leaves the decision to Shen Qianye, reuniting her with the Prince.

The Crown Prince offers to protect Shen Qianye at his estate, but she chooses to stay with Pei Su to uncover the truth, leaving the Prince heartbroken. Meanwhile, Pei Su is also investigating the massacre because the killer used his exact spiritual techniques, and he deliberately leaks clues to her, revealing he knows she isn't the real Shen Qianye. Shen Qianye plants traces of her wood soul at the Crown Prince's estate to test him. When the Prince responds by setting a deadly trap to eradicate Xihe, she realizes her former lover is now her enemy and strikes a new deal with Pei Su.

Shen Qianye plots to become the Crown Princess again to manipulate the Crown Prince and expose his crimes. Unbeknownst to her, the Prince's deadly trap was actually aimed at Pei Su, who had framed the Prince by replacing Shen Qianye's begonia flowers with phoenix flowers. Meanwhile, the Crown Prince attempts to turn the royal council against Pei Su by alleging he conspired with Xihe's family, but King Cangwu suppresses the discussion, fueling the Prince's resentment. Disregarding the danger, Pei Su remains fascinated by Shen Qianye’s past, while she focuses on awakening her wood soul to exact revenge.

To force Pei Su to help awaken her wood soul, Shen Qianye poisons herself with a binding vine, but Pei Su imprisons and flogs her instead. At death's door, her potential is triggered, and she awakens her wood soul after breaking through a dream confronting the hypocritical Crown Prince. Pei Su is injured defending her, revealing his harsh actions were intended to help her awaken her power. However, he then transforms into the Crown Prince within an illusion to confirm if she is Xihe. Sensing the trap, Shen Qianye refuses to admit her identity, demonstrating she can assist or harm him even without her full wood soul.

The Crown Prince attempts to arrest Pei Su using a token found at the Xihe estate, but Pei Su dismisses it as stolen. Jealous of Pei Su's superior spiritual talent and the King's favoritism, the Prince uses the opportunity to warn him and discovers Pei Su's injuries. Shen Qianye feigns weakness, claiming Pei Su tortured her, and stabs him to regain the Crown Prince's trust. This ruse, coordinated with Pei Su, allows her to return to the Shen family, secure an invitation to the Royal Banquet, and enter the selection to become Crown Princess. Meanwhile, the Crown Prince plots to exploit Pei Su's revealed weakness.

Upon returning home, Shen Qianye overpowers her hostile sister, Shen Qianling. When Qianling's mother, Jian Eying, attempts to flog her in her father's absence, Shen Qianye outsmarts her by orchestrating a public scene that humiliates Eying in front of her father and his colleagues. Learning that the Crown Prince escorted Shen Qianye home, her father decides to submit her name for the Royal Banquet selection in hopes of gaining imperial favor. Shen Qianye arrives at the banquet hall steps filled with nothing but a desire for vengeance.

At the banquet entrance, the Crown Prince behaves intimately with Shen Qianye and secretly informs her that Pei Su will die tonight. Despite her concern over it being a full moon night, she chooses to enter the banquet, satisfying the Prince's test. Inside, she senses Pei Su is in danger through their spiritual bond. When Qianling tries to humiliate her with a frog, Shen Qianye pretends to share Xihe's fondness for frogs, deliberately disgusting the Crown Prince. This provides her with an excuse to slip away from the banquet and rescue Pei Su.

Shen Qianye allows Pei Su to drink her blood to survive the full moon but then stabs him in the chest. Knowing the Crown Prince is spying on them, this act—combined with her mimicking Xihe's old expressions—successfully dispels the Prince's suspicions about her loyalty. She then prompts Pei Su to report the Prince's assassination attempt to King Cangwu, who is content to let them weaken each other. Pei Su discovers his full-moon affliction involves a royal curse, while Shen Qianye learns that the original Shen Qianye was betrothed to Cheng Qi, Xihe's former subordinate.

Cheng Qi returns from the military to propose to Shen Qianye, creating a scandal regarding her concurrent selection as Crown Princess. The situation escalates when the Crown Prince and Pei Su arrive at the Shen estate. Shen Qianye skillfully shifts the blame to Jian Eying's poor management, defusing her own crisis. However, the three men break into a chaotic brawl. To stop the fight, a desperate Jian Eying agrees to punish her own daughter, Qianling, as demanded by Shen Qianye. Enraged by her daughter's suffering, Eying plots to take Shen Qianye’s life.

Shen Qianye rejects Cheng Qi’s attempt to elope with her, aware that Pei Su is lurking outside. While both she and Pei Su maintain a strict partnership, they secretly care for each other as they investigate the Crown Prince. However, Pei Su discovers his illness stems from a poison linked to the Queen and King Cangwu. The King reprimands the Queen for the chaos at the Shen estate, and the Queen projects her anger onto Jian Eying. Strained by the abuse, Eying decides to stop obeying the Queen and invites Shen Qianye to a royal audience.

The Queen threatens Shen Qianye and attempts to kill her with royal poison inside an abandoned palace. Shen Qianye coaxes a confession out of her, linking the Queen to the Xihe massacre. Suddenly, Jian Eying activates a hidden array, assassinating the Queen to frame Shen Qianye. Pei Su arrives to execute Eying as revenge for his poisoning, but the poison causes him to lose control and attack Shen Qianye. She neutralizes the poison, breaks the array, and sends the unconscious Pei Su away. The Crown Prince arrives and witnesses Shen Qianye using Xihe's wood soul, confirming her true identity.

The Crown Prince discovers a black mark on Jian Eying’s body identical to the one from the Xihe massacre, intensifying his search for the truth. Pei Su inspects Eying's body and realizes his uncontrollable full-moon states mean he might be the actual killer. The Crown Prince confronts Shen Qianye, accusing Pei Su of the massacre, but she dismisses it as a frame-up. Unbeknownst to her, Pei Su has already intercepted the evidence from the archives. When she warns Pei Su, he hides the truth, confirming it is a royal plot. The Crown Prince then proposes marriage to her.

The Crown Prince proposes to the Shen family. Recognizing the marriage as a mutual trap, Shen Qianye uses Pei Su to advance the wedding, while the Prince plans to capture Pei Su during the upcoming full moon. On the wedding night, as Shen Qianye uses her blood to suppress Pei Su's poison, the Crown Prince ambushes them. To protect her, Pei Su admits she is Xihe and triggers a forbidden technique to kill the attackers. Recognizing the exact execution style from her family's massacre, Shen Qianye realizes Pei Su was the killer.

Devastated, Shen Qianye stabs Pei Su, who admits he cannot control his actions. The Crown Prince captures and tortures Pei Su, scheduling his wedding with Shen Qianye for the next day to consolidate power. Upon reflection, Shen Qianye suspects a deeper conspiracy. After Pei Su is rescued by his subordinates, he tries to take her away, but she harshly rejects him. Accepting her identity, she reveals the truth to Cheng Qi. The Crown Prince proceeds with the wedding preparations, confident he can use Shen Qianye to control the fugitive Pei Su.

Pei Su attempts to rescue Shen Qianye before the wedding, but the Crown Prince ambushes him, forcing a confrontation where all parties acknowledge she is Xihe. She drives Pei Su away to protect him, secretly hoping he will return for her. Before the ceremony, the Crown Prince confesses he knew of the Queen's plot against her family but did nothing. Shen Qianye reveals she already knew of his complicity and only agreed to the marriage to utilize his status, reopen the case, and clear her family's name. Accepting his guilt, the Prince agrees to the marriage.