Lethal Investments opens seven years prior to the case that started it all: The Fourth Man. When Reiden Rosendal, a beautiful young woman, is found brutally murdered in her apartment, Inspectors Gunnarstranda and Frøhlich's top suspect is her lover--until he's discovered dead, too. When yet another body connected to Reidun surfaces, Gunnarstranda and Frøhlich must race against time to lay bare the murderer's dark secrets and stop the senseless killing.