On 10 April 1815, Tambora produced the largest eruption known on the planet during the past 10 ka. As described in Gillen D’Arcy Wood’s new book, the explosion was only the first dose of Tambora’s destructive power. In terms of its enduring presence in folklore, as well as its status in the scientific literature, 1816’s cold summer was the most significant meteorological event of the 19th century. After the tsunami and famine came cholera, opium, and failed Arctic expeditions.