On a suffocating summer afternoon, a gruesome murder shatters the quiet of Zhangjia Village. A woman is found stabbed in her sleep, the weapon still lodged in her chest. As seasoned detective Zhang Heping and his young partner Lee Emma begin their investigation, the evidence points to the victim's ex-husband—a man recently released from prison.

But something doesn't add up. The crime scene is too clean, the suspect's confession too convenient, and the victim's daughter, Meng Lyla, hides a chilling indifference beneath her grief. As Heping digs deeper, he begins to suspect that the real killer is still out there, watching, waiting.

With time running out, will Heping uncover the truth before another life is claimed? Or has the perfect crime already been committed?