The film revolves around a secret taxi company called Rainbow Taxi that specializes in seeking revenge for victims of crimes not protected by the law. Lee Je Hoon plays a former special forces officer, now taxi driver Kim Do Ki, who has innate instincts as well as a cold judgmental mind and a bold personality. Esom plays smart and savvy prosecutor Kang Ha Na. Kim Eui Sung plays Jang Sung Chul, the founder of Rainbow Taxi. And Lee Na Eun plays IT expert Go Eun, who works for Rainbow Taxi and finds personal information to help solve cases.