Set during the wave of democratization and cultural modernization that swept across South Korea in the early 1990s, a middle-class family hides a parallel treasonous secret: While seemingly ordinary citizens in the eyes of their friends, neighbors and even their children, both parents are actually elite North Korean spies working to bring down the South from within. Follow these two spies as they wrestle with conflicting feelings of patriotism, loyalty, identity and love, all while a ruthless Korean counterintelligence agent draws ever closer to discovering their identities.