Kim Hae-Il (Kim Nam-gil) is a priest. He believes that defending justice is needed in this world where people repeat their sins over and over again without remorse.

Koo Dae-Young (Kim Sung-kyun) is a detective, who is timid and yet talks alot.

Park Kyung-Sun (Lee Hanee) is a smart, pretty and ambitious prosecutor who is very good at her job.

Together, the three of them team up to solve the case of the mysterious death of an elderly priest.