Based on the webtoon series “Covertness,” Secretly Greatly stars three of Korea’s hottest young TV stars (Kim Soo-Hyun, Lee Hyun-Woo, Park Ki-Woong) as a trio of elite North Korean sleeper agents who have lived undercover in South Korea for so long that they now believe their own cover stories as an average joe, a wannabe singer and a high school student. Finally they get their first mission: kill each other. If they don’t get the job done, Pyongyang will send a hit team to take care of things.