It takes a special turn of mind to even think of writing a history of artificial light. But Jane Brox takes this curious, thin slice of history and makes of it a dazzling epic. In her hands, the 1698 building of the first offshore lighthouse plays like a battle: the builders are beaten back and washed away by the ocean, over and over again, until they finally make it stick. Brox takes us through the age of gaslight and arc light and into our strange present, in which true darkness is a precious vanishing resource, even at night, and we read by the light of our own glowing books.