The French have a word for it: le bestseller. The Mangrove Chronicle is John Treherne's fourth in as many years. His is an appropriately unusual story, as writers go, not least because it begins at an age by which most writers have a firm sense of their métier, and scientists have firmly established careers. Treherne is a zoologist: he runs the unit of Insect Neurophysiology and Pharmacology at Cambridge University, a group of two dozen researchers supported by the Agriculture and Food Research Council. He is a Fellow of Downing College. Scientists live in an intensely competitive world, and the best ones work obsessively, driven by macho peer-group pressure. What they do not do is write novels. So far, so simple. Then, when Treherne was about fifty, came one of those human physiological changes often associated with aging: he found he required much less sleep. Instead of writing more scientific papers, or even reading them, he decided to use this 'found' time to solve a puzzle that had come his way when he visited the Galapagos Islands on a series of scientific expeditions. Partway through this first book he wanted reassurance, so he showed his manuscript to a friend who was, and is, a professional writer. The friend had a friend in publishing, and took the half-manuscript away. Not long after, Treherne found himself sitting across an editorial desk at Cape, watching a cheque for two thousand pounds being pushed toward him. 'We think,' said the Editor, using the ...