The Constant Gardener, by John le CarrΘ (Coronet, £6.99 in UK )

Justin Quayle is a mild-mannered, quintessentially English diplomat on a posting in Nairobi

Justin Quayle is a mild-mannered, quintessentially English diplomat on a posting in Nairobi. His much younger, spirited wife, Tessa, has become involved in uncovering the illegal drug-testing activities of multinational pharmaceutical companies among the poor in Africa. At the start of the book she is found brutally murdered in a remote part of Africa. This shocks Justin out of his freesia-growing complacency and sets him on the trail of her killers. He's an unlikely hero and as his investigation unfolds, his love for his dead wife becomes the book's strongest subtext. It's not one of those feel-good "little guy against the multinationals" yarns - le CarrΘ is too worldly wise for that - but a moving, powerful story.