Kim Je-ha gets a phone call and heads to a building where the offices of presidential candidate, Jang Se-joon, is located. While Je-ha is securing Jang's banner outside, he witnesses the candidate having an affair.

Je-ha wants to live a quiet life. But Yoo-jin, Jang Se-joon's wife, uses governmental authority to track him down. As the people around Je-ha are put in danger, Je-ha decides to strike back.

Yoo-jin's trap for Je-ha fails and ends up being his hostage. Meanwhile, the link between Je-ha and Park Gwan-su's past begins to reveal itself.

Je-ha fails to attack Park Gwan-su, and just as the walls are about to close in on him, Yoo-jin appears. The two become allies, and Je-ha ends up joining JSS with the code name, K2. He's assigned to guard An-na, the secret daughter of Jang Se-joon.

Je-ha becomes an indispensable member for JSS. And as he guards An-na, he starts falling in love with her.

Je-ha receives permission to enter Cloud Nine. He starts to find out the truth of what happened in Iraq. And one by one, details of Je-ha's past come to light.