Chen Kaiqing gathers information about the suspect, Mai Zhihong, and asks Officer Zhang to investigate with her. However, Officer Zhang is preoccupied with other matters and cannot leave. Upon hearing that Chen Kaiqing intends to go alone, he assigns Yang Guangyao to accompany her.
While walking down a familiar alley after shopping, Zhang Tianming is flooded with memories of his firefighter father and the horrific scene of his murder. Shaking off these painful memories, Zhang Tianming rushes to visit his mother in the hospital. He brings her sesame dumplings and comforts her with a fabricated story to ease her worries.
Meanwhile, Yang Guangyao and Chen Kaiqing go out for a meal to discuss the case. He notices her constantly on her phone and can’t help but tease her about it. When a third officer joins them, they discuss Mai Zhihong and his family, including his sister, Mai Xiaojuan. Back at the police station, they examine surveillance footage but find no leads. Restless, Yang Guangyao finishes his snacks and heads out to investigate on his own.
He visits the funeral home and inquires about Mai Zhihong’s presence at his mother’s funeral. A witness recounts the events of that day, providing valuable clues. Yang Guangyao immediately calls his colleagues to share the information. Following these leads, they search for Mai Zhihong’s missing sister. After hearing a passerby’s comment, Yang Guangyao has a sudden realization and rushes towards the woods, ignoring Chen Kaiqing’s attempts to reach him. He discovers Mai Xiaojuan and her daughter tied up in a cave and tries to free them. Suddenly, Mai Zhihong returns and attacks Yang Guangyao with a wooden plank. Despite being injured, Yang Guangyao fights back and manages to rescue Xiaojuan’s daughter, Qiaoqiao. As Mai Zhihong tries to escape, Chen Kaiqing arrives and confronts him, but he manages to flee during the struggle.
Back at the police station, they discuss the case, but Yang Guangyao remains convinced that Mai Zhihong is the killer. He returns to the cave to investigate further and discovers a cell phone. To his surprise, Mai Zhihong appears on the screen, taunting him. Yang Guangyao vows to catch him. He keeps the phone instead of handing it over to the police, hoping to use it to track Mai Zhihong.
The next day, while eating instant noodles at the police station, Yang Guangyao notices a scar on Chen Kaiqing’s arm identical to one his daughter has. He is stunned. He observes her closely while working, trying to find more similarities, but is disappointed when they don’t match up.
After visiting her mother, Chen Kaiqing receives a call from the caregiver informing her that Zhang Tianming’s mother has wandered off. She rushes out to find her. Later, Zhang Tianming finds his mother and brings her back. He confides in Chen Kaiqing about his father’s murder, and she sympathizes with his pain.
Meanwhile, Yang Guangyao continues to investigate the case relentlessly. He examines a photo of the deceased and starts to question his previous assumptions. After the forensic examination, the medical examiner praises his insight. As they leave, someone mentions that the medical examiner is Chen Kaiqing’s father.
