"The sea fogs" is an account of a trip to Napa Valley (California), first published by Stevenson in short story form in 1879. During this trip the writer's health worsens: influenced by disease, Stevenson began writing of poisonous mists from the sea that hover over the valley below. Then, gradually, the idea takes shape and boundless cloud turns hills and Islands in a giant ship. A few pages, but intense and visionary, issued from the mind of one of the most important writers of all time.