In the third episode of "The Price of Confession," the drama kicks off with a heart-wrenching conversation between Yun-su and Mo Eun, their voices echoing through the thin wall that separates their cells. Mo Eun informs Yun-su of her plan to call for a jury trial before confessing to Ki-dae's murder, but hints at a hidden agenda, teasing the audience with a mystery yet to be unraveled.
As the trial is delayed, public opinion begins to fester, questioning the prosecution's decision to keep Yun-su in custody. Dong-hun, determined to get to the bottom of things, brings both women in for questioning. They travel together in the same bus, and as they do, Yun-su executes a subtle attack on Mo Eun—a signal, as later revealed, that she has accepted Mo Eun's offer.
Upon arrival, Yun-su refuses to speak without a lawyer present, while Mo Eun bravely answers all of Dong-hun's questions about Ki-dae's murder. Her meticulous details even include a drawing of the studio where he died. However, Dong-hun's suspicion grows when she recalls trivia from five months ago and questions her lack of a motive—a common topic among killers.
Dong-hun and his colleague, Mr. Hwang, obtain a warrant and investigate the solitary confinement cells in the prison. While they find a hole in the wall between other cells, Mo Eun and Yun-su's cells remain unscathed—a detail that flashes back to Mo Eun chewing on rice and cunningly stuffing it into the crack in the wall.
Dong-hun then conducts a thorough search of Yun-su's room and even orders a strip search of her and her roommates. When nothing is found, he warns Yun-su about associating with Mo Eun. As per Mo Eun's instructions, Yun-su hires a little-known lawyer named Jeong-gu, asking him to secure her release on bail as soon as possible.
Dong-hun's next move is to order a polygraph test. Yun-su denies it, but Mo Eun agrees. All her answers appear truthful, frustrating Dong-hun as he forcefully takes the mic and demands to know why she did it. Mo Eun simply laughs in response, rendering the test inoperative.
Jeong-gu then turns to the media, using them to paint a sympathetic picture of Yun-su as an innocent mother wrongly imprisoned. Eventually, Yun-su is granted bail and allowed to leave, reuniting with her daughter as they drive away. In that moment of freedom, we learn the rest of their deal with Mo Eun—there is one more person she wanted to kill but couldn't. As part of their agreement, Yun-su must now take on that task herself.
