Secretly Greatly

Three elite North Korean sleeper agents live undercover for so long that they believe their cover stories are their real identities. They're shocked when they are ordered to kill one another or face death at the hands of an elite hit team.

Secretly Greatly is a 2013 drama action movie directed by Cheol-soo Jang, starring Son Hyeon-ju, Park Gi-woong, Lee Hyun-woo. It holds an IMDb rating of 6.8/10 from 5,766 votes and runs 2h 4m.