The sequel opens three years after the unsolved demise of the first installment's hero, NSS agent Kim Hyun-jun (Lee Byung-hun). NSS Task Force A Team Head Jung Yoo-gun (Jang Hyuk) and his team are busy trying to unveil the true identity behind the secret organization IRIS while also acting as bodyguards at a South and North Korea summit. Operative Jung must also transport rogue NSS director Baek San (Kim Yeong-cheol) to safety, but is ambushed by IRIS and mysteriously disappears. He is presumed killed in action. Later, upon the sudden return of Jung, fellow NSS agent and love interest Ji Soo-yeon (Lee Da-hae) discovers that his disappearance is all part of a large-scale conspiracy.