On Labor Day in 2004, the seven-year-old daughter of police officer Li Ping vanished without a trace while chasing two classmates. During the investigation, Li Ping caused a suspect's accidental death and was sentenced to prison.
After his release in 2008, Li Ping discovered that his mistake had nearly destroyed the family of the suspect who died, while the real culprit was someone else entirely. He then embarked on an eight-year hunt for the truth, only to uncover another secret concealed behind the disappearance.
In September 2015, an arson attack took place in a shantytown in the western suburbs that was being demolished. The fire started in the very place where Li Ping's daughter had vanished eight years earlier.
What role did the two classmates of Li Ping's daughter play in the disappearance eleven years ago, and how was the arson eleven years later connected to it?