The Constant Gardener by John Le Carr

DON'T be put of by the dull and uninspiring title. The Constant Gardener is not a horticultural thriller and the leading man is not, thankfully, Alan Titchmarsh.

The hero is Justin Quayle, a well-educated and respected middle-ranking career diplomat working for the British High Commission in Nairobi, Kenya, who likes to dabble a bit in the garden.

But his world is turned upside down when his young wife, Tessa, is murdered in northern Kenya. Missing is her travelling companion and alleged lover Dr Arnold Bluhm, a Belgian aid official.

Dedicated to the cause of women's rights in Africa, Tessa's most recent target had been the exploitation of Africa by giant pharmaceutical companies. She claimed that native Africans were being used as human guinea pigs to try out new drugs, with fatal consequences.

But her pleas to the British government for action fell on deaf ears, and following her murder, Whitehall is desperate to avoid a scandal.

Shocked by his wife's death and the Foreign Office's decision to suppress the truth, Justin sets out to pursue Tessa's killers. His quest takes him to the Mediterranean island of Elba, to northern Germany, Canada and south Sudan, and offers him an insight to a side of his wife he never knew.

The Constant Gardener is vintage Le Carr, far better than his recent novels Our Game and Single And Single.

It's a powerful and thought-provoking thriller with an unhealthy mixture of murder, greed and corruption and written in Le Carr's inimitable style. What more can you ask for?