When Amitav Ghosh began the research for his monumental cycle of novels, ‘The Ibis Trilogy’, ten years ago, he was startled to find how the lives of the 19th century sailors and soldiers he wrote of were dictated not only by the currents of the Indian Ocean, but also by the precious commodity carried in enormous quantities on those currents: opium. Most surprising at all, however, was the discovery that his own identity and family history was swept up in the story. ‘Smoke and Ashes’ is at once a travelogue, memoir and an essay in history, drawing on decades of archival research. In it, Ghosh traces the transformative effect the opium trade had on Britain, India, and China, as well as the world at large.