The relationship between Detective Eva and her colleague Floris comes under heavy pressure. Floris is in prison for stealing four million euros of government money and Eva is trying to forget him. But if Floris is released earlier by a procedural error and joins a bunch of criminals, they meet each other, as opponents, in a world where not everything is what it seems. And where trust proves vital - The defector (De Overloper) is a Dutch television film and forms a bridge between season 5 and 6 of the television series Flikken Maastricht. Important developments from the series have been incorporated in the film. However, the film can also be seen as a stand-alone film without the need for prior knowledge.