Kate Marshall's detective agency gains popularity when she and her partner Tristan are hired to investigate a crime that happened over ten years ago. Twelve years earlier, a determined young journalist named Joanna Duncan uncovered a political scandal that had serious consequences. But the journalist herself disappeared without a trace, leaving no trace behind. When Kate and Tristan study the case materials, they discover the names of two young men who also disappeared at that time. Gradually, they investigate the last days of their lives and realize that Joanna may have stumbled upon something much more sinister than anyone first thought: the identity of a serial killer preying on people who were then the most vulnerable in society.