A hard-boiled investigative comedy drama that centers around the insurance investigator Koo Kyung Yi who investigates a murder case. Koo Kyung Yi, an intelligent woman who solves cold cases for the thrill of cracking the case rather than bringing justice to the world. By hook or by crook, she ferociously chases the truth behind every case.A college student who is a serial killer plots an accidental murder case to defraud her insurance money.