The series is based around the murder investigation of Prime Minister Olof Palme. The head of the National Intelligence and Security Service, Lars Martin Johansson, is frustrated that the Palme murder was never solved. Could he have prevented the murder had he done his job differently then? He will have the opportunity to create a parallel investigation alongside the regular Palme Commission. He names a new group of strategically chosen people who he believes may be able to shed new light on the research. Someone must have seen or heard something. Many people involved appear to have played a dubious role during those events. A lot has gone under the rug and Johansson and his team go from one surprise to the next.