John le Carré's novel opens with the gruesome murder of the beautiful Tessa Quayle and the mysterious disappearance of her presumptuous African lover and traveling companion who has vanished from the scene of crime. Tessa had been compiling data against a multinational drug company that uses helpless Africans as guinea pigs to test a tuberculosis remedy with fatal side effects. Her much older husband, Justin, a career diplomat at the British High Commission in Nairobi, sets out on a personal odyssey in pursuit of the killers and to learn of their motive--a motive that could provide answers to their hideous crime.