Tessa Quayle, a brilliant and beautiful young social activist, has been found brutally murdered by Lake Turkana in Nairobi. The rumours are that she was faithless, careless, but her husband Justin, a reserved, garden-loving British diplomat, refuses to believe them. As he sets out to discover what really happened to Tessa, he unearths a conspiracy more disturbing, and more deadly, than he could ever have imagined.