Ye Yiyun received an order from his superiors to lurk back to the city to investigate a drug trafficking case, which led to a murder case. The murder of his mother's best friend made Ye Yiyun feel that the matter was full of mysteries, so he secretly started investigating, but he repeatedly put himself in danger. The two men around her risked their lives for her, but each had their own plans... When all the mysteries were solved and the murderer appeared, the drug trafficking case that had been hidden in secret also came to light...
