On a sweltering summer day, Sound Effect CHEN JIA HUI’s fiancé ZHONG JIA HAO suddenly disappears, leaving behind only a vague voice message. As the police investigate, the shocking truth about his use of multiple identities to commit emotional fraud is revealed. However, the matter was not over, and a year later, ZHONG JIA HAO’s body was found in the river under the identity of another person, CHEN JIAN KUN, and the cause of death was unknown. During the police investigation, CHEN JIA HUI’s behavior and the hidden details in the voice file reversed the direction of the investigation. As the truth emerges, the voice becomes the key to unraveling the mystery – it not only records the truth of the past, but also exposes the dark secrets of CHEN JIA HUI’s heart. A “perfect murder” of love and betrayal is quietly buried in the frequency of disappearing.