Tan Jingtian (Zhang Yao) and Jin Ling (Chu Yue) went to Thailand to participate in exchange studies. They met Thai police chief Valarillo because of a murder case of a fallen woman caused by smuggling Indian butterflies. The three of them began to work together to solve strange cases. However, the crisis was around them. In the process of solving a serial murder case, they found that Jin Ling had become the next target of the murderer.