A murderer goes loose in the middle of the idyllic Swedish island Sandhamn and it's up to crime investigator Thomas Andreasson to solve the case. THe gets unexpected help from Nora, a bright female attorney, and their cooperation leads to more than he had expected.

It is a beautiful summer morning on the island of Sandhamn in the Swedish archipelago. In the middle of an idyllic beach scenario, a dead man's body floats up to the surface entangled in a fishing net. Crime inspector Thomas Andreasson from the Nacka police is called to the scene. He has a personal closeness to the island, but it is with a dark past, fresh in his memory, he returns to Sandhamn to solve the case. It soon turns out that the truth behind the murder is more complicated than expected and goes further back in history than anyone could have imagined. As more crimes are committed, the pressure increases on Thomas and his colleague Carina Persson. The clues are few and they are forced to work hard during the hot summer days in the archipelago. Thomas gets unexpected help from the summer guest, banking lawyer and mother of two Nora Lindé, a cooperation that Nora's husband Henrik is strongly against. The Sandhamn Murders is based on Viveca Stens crime novel "I de lugnaste vatten".