Season 1 of Shadow Lines premiered on October 4, 2019.

Helsinki 1955: During the upcoming presidential election, the KGB, CIA and other intelligence services will do their utmost to ensure that the president will be of their chosen. Nyrkki, secret team of Finnish spies effectively protects Finland's independence when the newest member of the group compromises everything in search for the truth about their own past.

Season 2 of Shadow Lines premiered on September 6, 2021.

Year 1956. Kekkonen has been elected as the President of Finland. As the Republic struggles in the pressure of the Eastern and Western superpowers, the secret intelligence unit Nyrkki faces a threat from its own past.