At 3 o'clock in the morning, I received an order for milk tea with a "rebate of 999 yuan". The note said, "Open the box when it is delivered and wait 7 minutes and 30 seconds, otherwise someone will die." There was only a cup of blood milk and a torn police card in the box. I was led along by the navigation system and found that the route happened to pass through every dumping point of the unsolved "serial throat-cutting case" five years ago. What's even more frightening is that the mobile phone number of the person who placed the order is displayed in the background - it's my girlfriend, a detective who died in the line of duty last year.