In the early spring of 1999, not long after the anti-drug detachment of Harlan City was established, the aftermath of the collapse of the "Snow Angel" drug cartel was still lingering. However, a new synthetic drug of unknown origin, "Han Yan", appeared on the market. It was more addictive and more disguised, and was subtly related to the "Snow Angel" formula. What is even more disturbing is that in many cases related to "Han Yan", there have been clues pointing to overseas drug trafficking networks and Jiang Xiaohai's past connections. Zheng Bei and Gu Yiran led the newly formed team. In the process of solving the new case, they were forced to re-touch the past mixed with guilt and pain, and at the same time faced a new cross-border drug control challenge.
