The Exorcist's Meter follows Ma Kwai, a kind-hearted but cynical taxi driver who works the night shift in Hong Kong. His mundane life takes a supernatural turn when he accidentally awakens a stone spirit, Shek Kam-dong, who has been trapped for centuries. As Ma Kwai begins to see spirits and demons lurking in the city, he finds himself thrust into the role of an unlikely exorcist, tasked with protecting the living from malevolent forces. As the series progresses, Ma Kwai discovers that his ability to see the supernatural is tied to his own mysterious past and a tragic childhood event. Alongside his growing bond with the spirit Shek Kam-dong and a local doctor named Dr. Chong, he must confront his fears and navigate the thin veil between the human world and the spirit realm, all while balancing the demands of his taxi driving career.