On New Year's morning 2013, a passerby finds the body of 48-year-old Marja Nijholt from Enschede in the driveway of a house in Oss. She was killed by knife stabs. After two years of police investigation, the case is stuck. Hundreds of ordinary Dutch people care about Marja's fate. They form the Bureau Dupin research collective and do everything they can to uncover the truth.