J. G. Ballard’s fourth novel, which established his reputation as a writer of extraordinary talent and imaginative powers, tells the story of a physician specializing in the treatment of leprosy who is invited to a small outpost in the interior of Africa. Finding the roadways blocked, he takes to the river, and embarks on a frightening journey through a strange petrified forest whose area expands daily, affecting not only the physical environment but also its inhabitants.