Realtor Jung-tae's hobby is sneaking into strangers' homes and peeping into their lives. One day, an unfamiliar face in the area grabs his attention – an Instagram star, So-ra. Miraculously, So-ra leaves her house key at Jung-tae's agency and Jung-tae visits her home whenever he can, thrilled and excited. Like any other day, Jung-tae makes another visit and finds what he hadn't expected: the dead body of So-ra. Jung-tae is shocked and he can't call the police and report. But when he returns few hours later with a client… So-ra’s dead body is gone! Days later, Jung-tae receives a red note saying 'It was you, right?'. Even worse, all evidences say that Jung-tae is the criminal. Can he find the real killer and clear his name?