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.
A by-the-book police officer is assigned to secretly investigate a team leader who believes that the rules shouldn't stop an investigation. As the officer investigates further, his own attitudes begin to mirror the team leader's.
Woo-ri, 32, and Ja-young, 28, who both dislike being alone but have particular anxieties when it comes to dating, meet through an app.