"Detective" is a screen adaptation of a famous novel from 1997. In the series, we meet Sergeant Malcolm Ainsley. Once a man of the cloth, he lost his faith and joined the police force. Now a detective, he investigates the case of an unusual killer who sees himself as God's avenger. It seems that the captured maniac deserves the death penalty by lethal injection. However, the complex puzzle that the police officer uncovers is connected to him and his past.