When Guo Baifei, Jiang Xiwen and Liu Li first left school more than ten years ago, they had a deep relationship with Sergeant Luo Youbang, the fourth master and apprentice.During an operation three years ago, Bang was shot dead by gangsters and seriously injured and fell into a coma. Wen blamed Fei, and the friends parted ways since then.

A case of mutilation and murder of a young girl occurs in the city. The victim is related to a human trafficking group. Wen, who is affiliated with the Intelligence Division, is responsible for investigating the group's criminal evidence, while Fei, who is from the Crime Unit, is responsible for tracking down the murderer and dispatches trainee inspector Wen Jiali to infiltrate the criminal group.Fei and Wen coincidentally received mysterious mobile phone messages one after another, prompting clues to the murder. Their superiors merged the two groups and established the mysterious message intelligence branch (ASIB).ASIB is led by Fei Hewen, who work together to dismantle these mysterious messages that seem to come from the future and solve bizarre murders.

The message is mysterious and cannot be explained scientifically.Who sent the message?By people from the future?Or an unknown force of nature?Is the other party a friend or an enemy?