After a high-ranking North Korean official requests asylum, KCIA Foreign Unit chief Park Pyong-ho and Domestic Unit chief Kim Jung-do are tasked with uncovering a North Korean spy, known as Donglim, who is deeply embedded within their agency. When the spy begins leaking top secret intel that could jeopardize national security, the two units are each assigned to investigate each other.
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?
