During the 1950s, Helsinki was the focal point of the Cold War, as global powers and their intelligence agencies coalesced in the small neutral country that stood between the East and the West. Shadow Lines is an international spy thriller that follows a secret intelligence team whose mission is to defend the independence of Finland no matter the cost.

An ex-terrorist, Madina Taburova, who was presumed dead, turns up in Helsinki seeking political asylum. Using a fake identity, the Intelligence Agency officer Mari Saari has to befriend this ex-terrorist to find out why she’s here. In order to uncover the mystery, Mari Saari has to form an unlikely partnership with an older streetwise narcotics cop. But everything is not as it seems.

Summer 2007, Finland. While the Kurtti are spending their annual holidays in their cabins in the land of a thousand lakes, the family is struck by a tragedy: Tommi, 2 years old, is killed by a gunshot. Elias, a 12-year-old neighbour, is blamed for the death of the child. 12 years later, the family receives a threatening anonymous letter and the secrets start to unravel, and show how far each of them are willing to go for their loved ones.

Liv, a young woman from Helsinki, suffers from chronic pain for which she has not received a medical explanation. When Liv's DNA sample is stolen from a biobank, she encounters Markus Volf, an information security agent who is investigating the burglary of the biobank for personal reasons. It turns out that Liv’s genetic heritage may have an answer to the future of all of humanity. Liv's inheritance is also of interest to the power-hungry siblings Yoana and Sasha Leon, who lead the largest Nordic life science company Rise. A chase begins where it is difficult to know who to trust.