Zhu Chaoyang is a young boy who constantly scores #1 academically at school, but is detested by others for his cold demeanor. His parents are divorced and he lives with his mother, Zhou Chunhong. His mother is often busy with work but is extremely strict on his studying. She also has a relationship with her co-worker but doesn't tell Chaoyang. His father Zhu Yongping is remarried to a younger woman named Wang Yao and has a daughter named Jingjing. Chaoyang's stepmother and stepsister dislike him and he has a poor relationship with his father.

One day, Chaoyang is approached by Yanliang, his former acquaintance. Yanliang introduces Chaoyang to his companion, Yue Pu (also known as Pupu). The two had escaped from the orphanage and struggled to live on the streets. Yanliang's father was a gangster and a former drug addict, and as a result, a police officer named Chen Guansheng tries to send Yanliang back to the orphanage. Yue Pu is a young girl suffering from asthma and Yanliang's only friend from the orphanage. She needs 300,000 yuan to cure her younger brother's leukemia. Chaoyang agrees to let them stay in his house while his mother is at work and the three develop a close friendship.

Zhang Dongsheng is a teacher who is in a failing marriage. He loves his estranged wife Xu Jing but she wants a divorce after having an affair. At the urging of Xu Jing's relatives, Dongsheng takes his in-laws to Liufeng Mountain. He asks his in-laws to help him fix his marriage, but they refuse for the sake of Xu Jing's happiness. Dongsheng then pushes his in-laws off the mountain cliff. This incident is unexpectedly recorded by the three kids, who visited the mountain to take pictures. Later, it is also implied that Zhang Dongsheng was involved in Xu Jing's death when unusual drugs were found in her body.

The three kids decide to hand in their camera in exchange for 300,000 yuan. They experience a series of events, including the death of Zhu Jingjing, in which Chaoyang was present, and Wang Yao is certain that Chaoyang was the perpetrator. Wang Yao repeatedly tries to harass Chaoyang and his mother in public. Zhou Chunhong breaks up with her lover and decides to spend more time with her son. Zhu Yongping also tries to develop a stronger bond with his estranged son and renews his son's interest in swimming. On the other hand, Yanliang meets his father, who is mentally ill and obsessed with pears. Although Yanliang tries to run away from Chen Guansheng several times, they begin to trust each other.

One day, Wang Yao's brother Wang Li learns of Jingjing's death and attempts to murder Chaoyang. Yanliang tries to help Chaoyang, and Chen Guansheng comes to their rescue. Chen Guansheng is stabbed by Wang Li while protecting Yanliang and is taken to the hospital. Wang Li forces Chaoyang into his car and takes him to an abandoned building. Zhang Dongsheng witnesses this, and unexpectedly takes Yue Pu to save Chaoyang. Despite Wang Li's tactics to force Chaoyang to admit he killed Jingjing, Chaoyang is saved by Zhang Dongsheng, who then murders Wang Li and takes his phone. Zhu Yongping and Wang Yao find out and tell Chaoyang not to tell the police about Wang Li's actions.

Chen Guansheng survives the stabbing and is certain he wants to adopt Yanliang as his own son. Yanliang initially refuses, but agrees after visiting his father one last time. Yue Pu eventually begins to trust Zhang Dongsheng after he saved Chaoyang and let her and Yanliang stay at his house. Zhang Dongsheng starts to forgive the three kids and gives them 300,000 yuan. However, this peace is disrupted when Zhang Dongsheng overhears Yanliang telling Chaoyang that he won't get rid of the backup copy of the camera roll. Zhang Dongsheng feels betrayed and forces Yanliang to give him the backup copy. He takes the backup copy and finds out that it is a fake. As a result, he hesitates to save Yue Pu during her asthma attack.

Zhu Yongping and Wang Yao arrive at the abandoned building to reprimand Wang Li, but are attacked by Zhang Dongsheng. Wang Yao is strangled while Zhu Yongping is stabbed. Zhu Chaoyang and Yanliang return to the building to find Yue Pu, and Zhang Dongsheng burns the building and escapes. The two kids survive the fire after Yanliang calls Chen Guansheng, but they find Yue Pu gone. Chaoyang tells Yanliang that there wasn't a backup copy in the first place and they decide to report Zhang Dongsheng. Police officer Ye Jun believes Zhang Dongsheng is suspicious and starts to investigates him.

Eventually, Chaoyang and Yanliang arrange a meeting with Zhang Dongsheng on a ship by the shore. Yanliang sends a letter to Chen Guansheng about Zhang Dongsheng's crimes and 300,000 yuan to save Yue Pu's brother. The two boys confront Zhang Dongsheng, but Zhang Dongsheng tells Chaoyang to stab him to revenge Zhu Yongping. Chaoyang hesitates and stabs Zhang Dongsheng in the shoulder but not in the heart. Zhang Dongsheng doesn't kill the two boys because he wants them to suffer for the rest of their lives like he did. Zhang Dongsheng also reveals that Yue Pu is alive and safe in the hospital. Yanliang then jumps off the ship, after telling Chaoyang not to become the second Zhang Dongsheng. Chen Guansheng, Ye Jun, and other police arrive and Zhang Dongsheng commits suicide. Chen Guansheng rescues Yanliang and Chaoyang returns to living a normal life with his mother. The ending is Chaoyang telling Ye Jun about how Jingjing actually died.

The Bad Kids (Chinese: 隐秘的角落; pinyin: Yǐnmì De Jiǎoluò) is a 2020 Chinese streaming television series that premiered on iQiyi on June 16, 2020, which tells a story of the web of consequences birthed among different families after three children accidentally film a murder. It is directed by Xin Shuang, and features an ensemble cast that includes Qin Hao, Wang Jingchun, Zhang Songwen, Liu Lin and Lu Fangsheng, with special starring by Rong Zishan, Shi Pengyuan and Wang Shengdi.