Sun Woo has a mysterious accident while on a mission in China; after returning to Korea, he is assigned to the information analysis team; the National Intelligence Service gets tense with a North Korean spy turning herself in.

Ki Chul, Hye Rim's former boss, suddenly shows up at her house and threatens to reveal her real identity to the world; Sun Woo gets closer to the identity of the man with a burn scar who killed his partner in China.

Ki Chul keeps pushing Hye Rim to bring Sun Woo to him; Hye Rim refuses to bring Sun Woo to him and she eventually decides to turn herself in; Sun Woo is investigating the subway bombing case.

Sun Woo suggests to Joong Hyuk an operation by using Soo Yeon as a double agent to find out the North Korean spies who came to South Korea; Ki Chul orders Hye Rim to watch Sun Woo's every move and to report to him.

Sun Woo is shocked by Soo Yeon's death but tries to save her family as promised; Joong Hyuk blames Sun Woo for the failure of the operation; Ki Chul finds out that Hye Rim deleted part of the wiretapping.

Hye Rim suspects that Ki Chul has also planted a wiretap at Yun Jin's apartment; Hye Rim is searching if Yun Jin's apartment is bugged, she becomes suspicious of Yun Jin's identity; Sun Woo gets close to finding out who Ki Chul is.