A strange murder case, a body that cannot be seen, a murderer who is always one step ahead of others, and an unpredictable crime method...
In a future where technology is developing rapidly, people are extremely dependent on AI technology. Detective Fei Cheng's AI was damaged for no reason. Fei Cheng, who was originally going to borrow a temporary AI, received a second-hand AI from a mysterious person. The AI uploaded the memory data of the legendary female detective Chang An from fifty years ago. The two will work together to face many murder cases.
And behind each of these cases, they all point to An's mysterious disappearance fifty years ago.
