Chen Tianshuang, having seen his buddy die right in front of him, chooses to leave the National Security system and become a humble fishmonger. However, he is recalled and sent to Taiwan, China, to infiltrate the local gang and uncover the smuggling routes. Upon arriving in Taiwan, China, he quickly adapts to the local lifestyle and social circles. Yet, the brutal gang wars and the harsh reality of his undercover mission are quietly looming ahead...