The Inside Story.

One day, a woman (Lee Soo-yeon) goes to a police station and claims she's confessing to a murder. The more surprising this is, she claims to be his wife. The police goes to the scene of the crime and sees a man (Choi Joo-hyeok) stabbed to death. Her husband is a well-known entrepreneur but he is found miserably dead. Soo-yeon's story is shocking. Her husband was the Devil himself. He treated his wife as a sexual plaything and even dared to covet her sister (Lee Ji-yeon).