The reason we do what we do is because it must be done. I believe that I fight for the peace and freedom of the land we live on. – Yoo Si Jin Descendants of the Sun Synopsis : The drama is about doctors and soldiers stationed overseas in war zones, and will be a human melodrama about the people who deal with life and death on the front lines. (Source : Dramabeans) MAIN CAST Song Joong-ki as Captain Yoo Si-jin (a.k.a. Big Boss) Song Hye Kyo as Doctor Kang Mo-yeon (a.k.a. Beauty) Jin Goo as Master Sergeant Seo Dae-young…