Each day, night shift taxi driver Ma Kwai drives female doctor Chong Tsz-Yeuk to and from work on time, cherishing the moments they share, without realizing that he is meant to be her guardian. One night, at midnight, when Ma Kwai is urinating on a highway, he accidentally breaks the spell placed on a hundred-year-old genie, Shek Kam-Dong, and starts having inconceivable experiences. He not only sees things that others around him don't see but also receives superpowers. Though Ma Kwai initially feels very annoyed at this turn of events, he later teams up with Kam-Dong to hunt demons for money.