The twelfth episode of "The Price of Confession" opens with a poignant flashback to a festive occasion at the university, where Young-in introduces Su-yeon to the esteemed university director, Mr. Kim. Amidst the merriment, Seo-won and Ki-dae join the group, and Director Kim proudly shows off the painting donated by Young-in and his wife, a masterpiece by the artist Sokoboako. However, Ki-dae's revelation that the artist had plagiarized an apprentice's work casts a shadow over the occasion and alters the director's perception of Young-in.
Following the event, Young-in persists in reaching out to Ki-dae, desperate for an apology now that the courts have cleared Sokoboako of any plagiarism charges. Yet, Ki-dae shuns his attempts at communication, turning a deaf ear to his calls and visits. In a moment of exasperation, Su-yeong decides to storm into Ki-dae's studio, her determination palpable in the tense air.
Meanwhile, Dong-hun and the others embark on a meticulous search of the house where the scuffle with Dong-uk occurred. They uncover Dong-uk's phone and realize that Young-in was the one who sent him the incriminating pictures. In the car, Mo Eun reveals her knowledge of Young-in's deeds, informing Yun-su that it was indeed Young-in who sent the threatening messages via text and revealing the boy who used to care for Se-hun's cats. The scene is fraught with emotion and a sense of impending revelation.
Who was the culprit behind Se-hun's tragic demise? A flashback reveals Mo Eun assaulting the boy immediately after her hospital exit. She interrogates him, enquiring about his vision. The boy's phone, linked to a pet camera, captured the entire gruesome sequence—first, Yun-su attempting to snuff out Se-hun's life, followed by the actual perpetrator, Young-in, clad in a black coat, who dealt the fatal blow. Mo Eun presents You-su with the complete video.
At the hospital, Dong-uk shows the detectives the video Young-in sent, depicting Yun-su's assault on Se-hun. However, a few minutes later, Dong-hun and Jeong-gu receive the full video from Yun-su herself. Yun-su calls, and Jeong-gu informs her that they know Young-in is the mastermind and that they should collaborate. But Yun-su has an additional confirmation to make and abruptly ends the call.
She and Mo Eun journey to her husband's studio, only to find Young-in already there. He's searching for the original print of Ki-dae's artwork, which holds an extra fingerprint. Mo Eun lurks in the shadows while Young-in rants at Yun-su for foiling their plan. A flashback unveils the couple's panic after Mo Eun's confession, as they both stalked Yun-su and snapped pictures of her. Ultimately, it was Young-in who claimed Se-hun's life. He also snatched the pet camera on his way out.
As for Mo Eun's fate, her phone's ringing lures her into view. After a scuffle, Young-in holds Mo Eun hostage, a knife at her throat. He threatens Mo Eun and orders Yun-su to pour fluid over Ki-dae's original print, destroying the evidence. Then he coerces Yun-su into killing Mo Eun to escape the predicament, but Yun-su refuses.
Mo Eun answers Yun-su's question about her motive for helping. She asserts it's because Yun-su has a life to return to. Taking matters into her own hands, she uses Young-in's knife to stab herself. At this juncture, Jeong-gu and Dong-hun enter the room. As Yun-su rushes towards Young-in in anger, Mo Eun pulls the knife out and stabs him. Yun-su holds onto Mo Eun as she bleeds out, asking why she did it. Soon after, Mo Eun passes away.
As the drama reaches its climax, Yun-su's fate hangs in the balance. The courtroom scene unfolds, where the full video from Se-hun's pet cam is played, revealing a heart-wrenching tale of coercion and guilt. Jeong-gu's poignant explanation of Yun-su's predicament with Mo Eun paints a picture of a desperate soul caught in a web of her own making. Ultimately, the judge's verdict brings a measure of justice as he declares Yun-su not guilty of Ki-dae's murder. For the other charges, a suspended sentence allows her to walk free, her burden lightened by Ko Dong-uk's petition in her favor—a last-minute heroic act that swayed the judge's decision.
Meanwhile, Jin Young-in and his wife's fate is revealed in a flashback that shatters the illusions of the studio fight. Su-yeon's violent act against Ki-dae, gleaned from another version of the artwork, is exposed. However, the truth is even more twisted as a flashback reveals that it was Su-yeon who snapped and killed Ki-dae in a fit of rage. Young-in, though present at the scene, tried to distance himself by leaving the room and covering everything with etching solution before switching the knives.
As The Price of Confession nears its end, Yun-su and Sop embark on a journey to Thailand, Sop now wearing Mo Eun's watch as a poignant reminder. They visit the school grounds where the refugee camp once stood, stopping at the spot where Mo Eun used to hang out with her friend. They hang up the watch on a sign as a silent tribute before walking away.
The final scene returns to the wedding day of Yun-su and Ki-dae, with So-hae and So-mang passing by. Yun-su waves to them from afar, her heart heavy with memories but her spirit soaring free after the ordeal she has endured. The drama ends on a note of hope and closure, as Yun-su embarks on a new chapter in her life—a life free from the shadows of guilt and confession.
