Descendant of the Sun Recap Episode 12
Credit Gif: JirominooThe explosive ending of Episode 11 has garnished high expectation Shi-Jin was on his way to the appointment with Argus to save Doctor Kang. He also called the Arab leader bodyguard to request the Final favor card (He used Mo Yeon's favor) of borrowing a Helicopter, since he doesn't want anything that he does in this solo black mission of his to be put onto paper. The Helicopter would be used as escape route for Argus, however it's obvious that it is mostly a bait tactics for Shi-Jin.
Seo Dae Young realize that something bad was going on when he tries to radio Big Boss. Shi-Jin had left his military issue gun, uniform and dog tags behind, and he realize that his friend was off to do some sort of damage and to save Doctor Kang. Which he learned later on was kidnapped, since he has been preoccupied by our army surgeon recovery more.