**

In the winter of 1996, the body of female college student Wang Ailian was discovered at the Jinghua Shipyard. The frozen body parts were wrapped in the title page of a psychology textbook - with half an unfinished equal sign drawn on it. For thirty years, everyone has been asking "whether she is pure", but no one has discovered: - The murderer stole the identity of the drowned child and remains in hiding until now - Veterinary drug anisodamine corrodes critical DNA - The truth about delayed rigor mortis is hidden in rural slaughtering techniques When the criminal investigation captain sincerely opened the new case file for 2025, the forensic doctor suddenly pressed down on page 7 of the report: "Look at the freezing curve... He is basically waiting for us to restart the investigation." Deep in the dock, under the unmelted ice, a recorder rustled: "The second phase of the game begins." (The first case in the book, the "six openings" and cross-provincial cold chain murder cases will be revealed later)