Chen Pan’er, a poor village girl, is chosen as a sacrificial bride for the River God because her family cannot afford to bribe the local magistrate. She attempts to escape but is captured and imprisoned with other young women, only to discover that the so-called ritual is a cover for human trafficking. Determined to fight back, Pan’er leads the girls in an escape attempt. Meanwhile, Wen Su secretly infiltrates the magistrate’s office to collect evidence of corruption and uncovers the trafficking operation. Mistaken for an enemy, he struggles to rescue the girls, but most are brutally killed. To save Pan’er from execution, Wen Su wounds her in a way that only appears fatal, allowing her to survive.

After being rescued, Pan’er realizes she has nowhere to return. Hoping to leave money for her sick mother, she sells herself into servitude and renames herself Chen Baoyin. She becomes a maid in the Wen household and is shocked to discover that Wen Su is the eldest son of the family. When the Princess Royal attempts to summon the handsome Wen Su, Baoyin cleverly helps him avoid her attention. Soon after, Wen Su tops the imperial examination, but the Wen family is falsely accused of treason and arrested. Before being taken away, Madam Wen entrusts Baoyin with protecting her younger daughter.

Baoyin takes the young Miss Wen to her married sister for shelter, only to be rejected out of fear of political repercussions. Keeping her promise, Baoyin raises the girl herself under the new name Baozhu. With the help of Luo Teng, a kind kitchen worker, they find a place to stay. Baoyin earns a living by selling food on a boat along the river and eventually learns that the Wen family is still alive in prison, though Wen Su has disappeared. During the Lantern Festival, she unexpectedly sees Wen Su serving as one of the Princess Royal’s male companions, leaving her stunned.

Misunderstandings between Baoyin and Wen Su are cleared when they reunite at a temple, where Wen Su is secretly carrying out a dangerous mission. When the Princess Royal unexpectedly arrives, Baoyin improvises by pretending they are lovers breaking up, hoping to protect him. Suspicious of their relationship, the Princess orders Wen Su to kill Baoyin, but the temple abbot intervenes and saves them. Although spared for the moment, both realize the Princess has begun to suspect their connection. Later, she surprisingly allows Wen Su to visit his imprisoned family, making her true intentions even harder to predict.

While visiting the imprisoned Wen family, Baoyin earns their gratitude for her unwavering loyalty. Wen Su, burdened by the humiliation of serving the Princess Royal to protect his family, falls into despair after overhearing his father’s hopes for him. Drunk and emotionally broken, he seeks comfort at Baoyin’s home. Baoyin encourages him not to lose faith and reminds him that all his sacrifices are for the people he loves. Sharing their deepest fears and hopes, the two grow much closer, and their mutual affection quietly begins to blossom.

After an embarrassing dream about Wen Su, Baoyin struggles to hide her feelings. Luo Teng mistakenly assumes Wen Su is Baoyin’s future brother-in-law, making Wen Su unexpectedly jealous. Meanwhile, Baozhu is bullied at school, and Baoyin fearlessly defends her, attracting the attention of the academy’s head. She is invited to the residence, only to discover that the mysterious head is actually the Princess Royal herself, setting the stage for another dangerous encounter.

At the Princess Royal’s residence, Baoyin witnesses the humiliating life Wen Su endures as one of her favored companions. Impressed by Baoyin’s courage and independence, the Princess offers her a position in the palace, but Baoyin refuses. Amused and angered, the Princess forces Baoyin and Wen Su into a cruel game involving random punishments. With Wen Su’s life at stake, Baoyin keeps her composure and succeeds in winning their freedom through her own skill. Although she leaves unharmed, the experience leaves a deep emotional scar on both of them. That night, Wen Su is forced to remain by the Princess’s side, further highlighting the sacrifices he continues to make.

Shaken by recent events, Baoyin decides she must become stronger and more independent. She sells her boat and invests everything in a risky pearl-trading venture on the eastern coast. Meanwhile, Wen Su secretly sells his treasured belongings to support Baoyin and Baozhu, only to learn that Baoyin has already left. Worried about her safety, he leaves a message asking her to hang a red ribbon by the river upon her return. After a successful journey, Baoyin rushes to the agreed meeting place. Though they narrowly miss each other at first, the two are finally reunited, sharing a heartfelt moment that reveals how much they have come to care for one another.