Ace NIS agent Jung Hae-seong is demoted after a mission failure. He goes undercover at a high school to locate King Gojong's missing gold, meeting his teacher Oh Soo-ah, who sees him as her lost first love, stirring old heartbreak.

After the public rates the judicial system corrupt, the Devil Judge is appointed to live stream his trials. A reformist judge is hired as a secret mole to keep an eye on him.

Hong Ji Ah is an exorcist who gets rid of unrested spirits to sell houses. Oh In Beom is a fake exorcist who calls himself a doctor of the paranormal to scam people. They serendipitously run into each other one day.