Taken against his will to the West, East German soldier Martin Rauch undergoes intensive training to become a spy and assumes a new identity as Moritz Stamm, an officer working for a top West German general.
Moritz is given a dangerous mission to steal a top secret security report from the hotel room of a visiting general during a security conference in Bonn, but things don’t go to plan and his superiors are baffled by the secret file.
Moritz bonds with General Edel at a NATO conference in Brussels and gets a mission to seduce Linda, the secretary of a top security analyst, and installs a microphone in her desk to connect her directly to NVA headquarters.
The bug in Linda’s desk is found and Nato goes on high alert. Moritz is forced to recognise the dark reality of the organisation he is working for, while Alex has a vicious row with his father. Meanwhile, Moritz and Linda spend some quality time together, and he reveals his true identity to her.
Tischbier turns up unexpectedly and conveys some shocking news. On his way home to become a kidney donor for his mother, Moritz must first deliver a package to a mysterious man in West Berlin.
Schweppenstette visits Moritz in hospital and insists he returns undercover and resumes his assumed identity. Alex takes General Jackson hostage and forces him to denounce US military plans in Western Europe.
Tischbier joins a student demo at the military base and has devastating news for Alex. Moritz informs his agency that Able Archer is just a drill. He tries to prevent them from attacking but only gets threats in return so he is forced to blow his cover.
Alex is forced to confront his own demons. Ingrid tries to save Thomas from prison. As the threat of a nuclear war continues to escalate, Moritz must do everything he can to prevent a catastrophe. He manages to cross the border and confronts Yvonne and Annett before reporting to the agency.