On 27 August 1883 the eruption of Krakatoa in Indonesia culminated in one of the deadliest volcanic events on record, with about 36,000 deaths attributed to it. Its ash and debris reached the upper atmosphere and produced unusual twilight colours around the world for years afterwards. Johann Kiessling's 1888 German study explained the effect as ash particles diffracting sunlight. The book's final pages feature chromolithographs made from watercolours by Eduard Pechuël-Loesche, a naturalist and painter. To test his explanation Kiessling built a fog chamber, which proved instrumental in the development of Charles Thomas Rees Wilson's cloud chamber. That device was used in particle physics to make the paths of charged particles visible. The book joins art and science in a single investigation of a mysterious sky.

Hampi is a UNESCO World Heritage Site in Karnataka, India, with more than 1,600 surviving remains spread over 4,100 hectares. It was the capital of the Vijayanagara Empire from 1336 to 1565. Travellers from Persia and Portugal described it as a prosperous, wealthy and grand city with temples, markets and farms along the Tungabhadra River. By 1500 it was estimated to be the world's second-largest city after Beijing, and probably India's richest at the time. In 1565 a coalition of Muslim sultanates defeated the Vijayanagara Empire, its capital was conquered and destroyed, and the city was left in ruins. Hampi remains a religious centre, with the active Virupaksha Temple at its heart.