In the first season, detective Sofia Karppi (Pihla Viitala, Ivalo) investigates the murder of one woman, with the help of her partner, the snob Sakari Nurmi (Lauri Tilkanen, Tellus). In the second season, the two start a new investigation when two corpses are found in a tunnel between Helsinki and Tallinn. This tunnel was still under construction when the bodies were found.
