Karl Heinz Lambert (Herbert Knaup), a member of an elite German police unit (SEK), becomes embroiled in a dangerous conspiracy after a routine operation goes wrong. While investigating a series of high-level corruptions involving political power and financial crime, Lambert discovers that an undercover operation thought to have been compromised years ago is still active. As he digs deeper, he must navigate betrayals within his own police force while grappling with his turbulent relationship with Melba (Katja Flint).