Set in Los Angeles and Taiwan, the protagonist Charles Sun is a member of the Taipei gang. He lives as a brutal killer. When his father is shot by a mysterious killer, Charles must go to Los Angeles to protect his mother and the completely unknowingbrother Bruce.

Mother Erin (Michelle Yeoh) has built a new life for herself and her son in Los Angeles, far away from her past in Taiwan.

Charles (Justin Chien), the eldest son of a gang leader, was trained to be a hard-hearted criminal.He travels to Los Angeles to protect his mother and brother, and finds himself torn between two choices: the life he grew up in and the life he can create for himself.

Bruce (played by Sam Song Li) came to the United States as a child and has little memory of Taipei and no knowledge of his family's past.When his notorious and respected brother shows up on his doorstep, Bruce is thrust into a world for which he is completely unprepared.

Alexis (Highdee Kuan), driven and ambitious, has a strong sense of justice and professional ethics since she was a child, and later became an assistant prosecutor.

TK (played by Joon Lee), is an aspiring gangster and Bruce's best friend since childhood. He hopes that he is strong, loyal and smart - but this is not the case, but this does not prevent him from trying.