In 2006, in a county town in the south, female college student Yin Lu was murdered. Due to the lack of clues, the case has not been solved. Lian Zhou is Yin Lu's boyfriend. In order to find the truth, despite everyone's opposition, he resolutely moved to the ancient city where Yin Lu last appeared. Under the cover of delivering gas tanks, he began a needle-in-a-haystack investigation. During this period, Lian Zhou forged a deep friendship with Fu Xiang, the criminal policeman in charge of the case. Lian Zhou also grew from a young, reckless and willful youth to a steady, calm and thoughtful adult. During the entire investigation, after an accidental long coma, due to the changes in the encounters of people and things involved in the case, Lian Zhou could not help but further reflect on what different meanings his actions brought to his own and others' lives.