The fifth episode of Pro Bono opens with Gi-ppeum receiving a text message, a video of Da-wit in an inebriated state "accepting" a bribe from Jae-beom. His sudden shift from checking on his security friend to boasting about his online reputation leaves her reeling with confusion. Her inquiries lead her to discover that he has been accused of bribery, and her heart sinks as she starts to act cold and distant towards him.
The Pro Bono team is invited to a human rights coalition's football match, and Da-wit goes from dreading the event to becoming fiercely competitive. The opposing team, the Yangchon team, is a formidable force while the Pro Bono team struggles to keep up. The moment of humiliation reaches its peak when Jun-u accidentally scores for the opposition.
We learn that Yangchon is a multicultural village filled with immigrants and biracial residents. The head cheerleader, Kaya, is a beauty with a modern edge, and she wants a divorce. Da-wit initially dismisses her case, believing her to be a gold digger who married for a South Korean visa. Even when he learns of her husband's pathological jealousy, verbal abuse, and controlling nature, he remains unmoved.
It is Yeong-sil who notices the cheap knock-offs Kaya wears, and Gi-ppeum jumps in with the revelation of Da-wit's bribe, accusing him of being cold and shallow. Yeong-sil calms the situation by suggesting a discreet on-site inspection. Their investigations reveal that Kaya is the governor's daughter-in-law, and everyone is envious, calling her promiscuous. The team is disheartened by the lack of solidarity, and Da-wit bluntly states that country folk are just as selfish as city people.
The influential Governor Cho invites them for dinner, and they meet Kaya's husband, Dong-min. His intellect is impaired due to a brain injury as a child, and he treats Kaya like a doll, possessively throwing her around.
In solitude, Gi-ppeum posits a question to Da-wit: "Is your village equally burdened with injustice?" He elucidates that the law is a one-sided scale, tipped towards the wealthy at the expense of the common folk. A flashback reveals that his mother's inability to sue a company for the loss of her hand due to lack of financial means. In the present, Gi-ppeum asserts that his newfound wealth and power should now serve as a beacon for the common man's cause. This conviction propels him to take on the case, despite resistance from his firm. Gi-ppeum leverages Da-wit's bribery video as a blackmail against Jung-in, successfully securing her support.
The investigation commences amidst the lingering shadows of the football match where Kaya's plight was initially covered up. She desires a quiet divorce, preferring not to stir a fuss. However, when she reveals bruises and strangulation marks on her neck, Dong-min is accused of attempted murder. A waitress testifies how some youthful male villagers provoked an intoxicated Dong-min by alleging Kaya's infidelity and showcasing her body. In Kaya's statement, she recounts Dong-min's return home, ransacking her wardrobe, seizing her phone, and locking her in. When Da-wit questions her, Kaya concedes that Dong-min later strangled her. Despite Dong-min's apparent distress, Kaya claims it was a mistake and he is not a bad person. The villagers' reluctance to testify leaves Kaya feeling ashamed by the attention she has brought upon herself. Gi-ppeum blames Da-wit for unleashing the case, only to be met with an exasperated retort from her that she can take over and is adept at blackmail. Her refusal to hear his side of the bribery accusations leaves him agitated, and she retreats to confide with her father about the difficulty of rebuilding trust after it has been shattered.
In the subsequent hearing, Dong-min maintains his innocence, claiming he did not strangle Kaya but rather grabbed and shook her in response to her announcement of leaving him. A furious Mrs Cho testifies that Kaya never intended to stay and is framing Dong-min to secure a divorce while retaining her visa. Her argument is bolstered by the local pharmacist's revelation that Kaya purchased birth-control pills after the incident. The defense deduces that Kaya faked the strangulation marks. The Pro Bono team makes their last-ditch effort with the village head, whose testimony is crucial. A flashback shows Yeong-sil persuading him to testify as he and his family lived in Germany for years, treated as outsiders. The village head testifies that Dong-min carried Kaya to his animal hospital after she passed out, and he even has photos he took because the marks looked critical.
As the drama unfolds, Da-wit suddenly requests a moment of solitude, confronting Kaya with a gaze that betrays her inner turmoil. The mark on her skin, a stark reminder of a right-handed individual's touch, stands in stark contrast to Dong-min's left-handedness. Kaya's secret purchase of morning-after pills rather than embracing a more regular form of birth control fuels the whispers that circulate like a dark fog, alleging she prefers the solace of an alcoholic beverage over dining alone with her father-in-law. The locks on her room, a tangible barrier, serve as a testament to her fear of an unwanted intrusion.
Kaya's tears fall like raindrops, validating Da-wit's hunch that Governor Cho had raped and strangled her. The discovery of DNA evidence leads to the arrest of the powerful governor, setting off a wave of emotions that threaten to swallow Kaya whole. Gi-ppeum urges her to not let love cloud her judgment, but Kaya, though she cherishes Dong-min in her own way, dismisses the notion with a scoff. Her determination to avoid returning home transcends even the love she bears for him.
The case nears its conclusion, only for Myeong-hun, the Chos' newly appointed lawyer, to throw a curveball by announcing that the marriage is invalid due to Kaya's pregnancy before she even set foot in South Korea. A flashback reveals Governor Cho's cryptic mention to Myeong-hun about Kaya's pregnancy line, a subtle but significant detail.
Myeong-hun's demand for an annulment and compensation of 100 million won sends shockwaves through Da-wit and Gi-ppeum, who panic over the potential consequences: Kaya's visa could be revoked, and she would be deported from the land she now calls home.
