Book excerpt: The short life of Robert Louis Stevenson (1850-94) was as adventurous as almost anything in his fiction: his travels, illness, struggles to become a writer, relationships with his volatile wife and step-family, friendships and quarrels have fascinated readers for over a century. In his time he was both engineer and aesthete, dutiful son and reckless lover, Scotsman and South Sea Islander, Covenanter and atheist. Stevenson's books, including Treasure Island, The Strange Case of Dr Jekyll and Mr Hyde and Kidnapped, have achieved world fame; others -- The Master of Ballantrae, A Child's Garden of Verses, Travels with a Donkey -- remain all-time favourites.