Song Ji Na takes a leave of absence from work and goes to find her sister Song Ji Hyun, who dissapeard.

Song Ji Na and her father file a report to the police about Song Ji Hyun disappearance

Song Ji Na meets Detective Park and they hunt down Lee Woo Hyuk, later Lee Woo Hyuk is arrested and has a cerebral seizure, after which he is taken to the hospital.

Song Ji Na and Detective Park go to detective Park’s friend to hack the security cameras, Song Ji Na's father kidnaps Lee Woo Hyuk.

Song Ji Na and Detective Park go to Song Ji Na’s father's place, where he is taken to the hospital. Song Ji Na goes to Charlie's store to find out the truth.

Detective Park is Exempted from Song Ji Hyun's case. Detective Jang Won Suk is assigned to the case and he obtains an order to inspect the water tanks for strange smells

A dead body is discovered in the water tank. Leter, Charlie made a porn video for Song Ji Hyun and posted it online.

An unknown person wearing a mask, breaks into Song Ji Na's house and attacks her, stealing her sister's laptop.

Song Ji Hyun is found, and the police started investigating Charlie over the video he made of her.

Detective Jang Won Suk investigates Song Ji Na. Later, Mr. Yang asked Song Ji Na to testify in the harassment case.

Nam Young finds out that Park is the criminal, and detective Jang Won Suk goes to arrest Park, but the Park manages to escape.

Park goes to Song Ji Na and confesses everything to her, Nam Young discovers that Park is not the murderer.