Chao Yang is the number one student at his school, but he has a complicated family situation. He hangs out with two "bad" kids from an orphanage. They go to the mountains to take pictures. Chao Yang takes a video of Pupu singing while they are on the mountain and captures a murder scene.
Dong Sheng recounts what happened before his in laws died. Chao Yang wants to report the crime, but his friends don't want to get involved with the police. The kids decide to write a warning letter to the murderer.
Chao Yang realizes that he knows the murderer. Pupu threatens Chao Yang's stepsister so she doesn't bully him, but somehow she ends up dead. The police officer hears her fall as he was catching Yan Liang.
Dong Sheng discovers who gave him the warning letter. The kids blackmail Dong Sheng for money to save Pupu's brother, but the deal doesn't go smoothly. Yan Liang almost gets taken back to the welfare home.
Chao Yang's stepmother goes crazy and attacks him, accusing him of killing her daughter. The bad kids steal the evidence back from the police officer's home. Chao Yang stepmother then goes after Chao Yang's mom. His mom's alibi blows everyone away.
The kids try to blackmail Dong Sheng for more money, but he won't give them anymore. Dong Sheng's wife leaves him.
Chao Yang hears that Dong Sheng's wife died and wonders if he murdered her. When Chao Yang goes to Dong Sheng's house, he ends up running into the police officer who was chasing Yan Liang. Dong Sheng is tracking the kids. Yan Liang decides to turn in the evidence to the police.
Pupu gets ready to go visit her brother, but Dong Sheng has bought the same ticket as the kids. Now's the stepmom's brother is trying to get Chao Yang to admit he killed the daughter
Chao Yang gets kidnapped by the stepmom's brother. Dong Sheng gives Pupu a ride to chase down the car. The cop becomes Yan Liang's guardian, and gets injured trying to protect him. Dong Sheng kills yet another person.
The police investigate Chao Yang's injury, but he lies about it for his dad. Dong Sheng find out the kids lied to him. Pupu is unconscious from her asthma.
Chao Yang didn't copy the card, so the other card given to Dong Sheng was blank. Dong Sheng has Pupu and wants to trade it for the other card. Yan Liang is angry at Chao Yang for lying. Dong Sheng kills some more people.
The two boys make it out of the burning factory, but Chao Yang lies about what happened. The boys call up Dong Sheng one more time and they have a final battle. Chao Yang finally tells the whole truth.
