Set 3 years after the first season, members of the National Security Service (NSS) team, including Jung Yoo Gun, Ji Soo Yeon and other agents attempt to pull the curtain on mysterious group IRIS. Agent Yoo Gun is the leader of the NSS TF-A team. While he goes up against Baek San, Yoo Gun becomes involved in a case which changes his fate forever.
Hae-gap is a director who makes anti-government documentary films. One day, Hae-gap’s son, Na-ra, runs away from home, but Man-deok, a freeloader living in Hae-gap’s house ends up bringing him back. Later, Man-deok raids the head developer of Deul Island to stop its exploitation, and Na-ra helps and ends up getting caught. In order to bring Na-ra out from jail, Hae-gap signs to stop making anti-government films and moves to Deul Island with his family. Na-ra sees his father leading a good, quiet life there and starts opening up. But when a construction company charges in to clear-out the island and the islanders fall at risk of losing their homes, Hae-gap leads a strike against it and his family fall in grave danger...
Upon getting out of prison, Deok-Bae meets his old buddy Dal-soo, who owns a restaurant. These two have never succeeded in life, and are constantly in and out of prison. Two others who happen to be in the same boat as Deok-Bae and Dal-Soo are ex-convicts. They have threatened to commit suicide unless traffic and unemployment issues are resolved. They are also unlucky enough to have been spotted at the scene of a crime. While these four are making big plans for their first success, the city becomes wrapped up in a serial murder case. In the meantime, an investigating team of veteran cops is formed in order to solve this case.
A man aids his friend by assisting him in disposing of the body of his ex-girlfriend.
Against the wishes and advice of friends and relatives, Chul-soo and Young-hui get married. They start their life together but because of their inability to communicate, their marriage falls apart and ends in divorce. Friends help them find a two-story house to live in. Chul soo takes the upstairs and Young-hui, the downstairs. From that moment there is constant interference and jealousy between the two. Young-hui eventually brings a man home to make Chul-soo jealous, which it does, even though he no longer has right to interfere in her life.