After fraudulently winning a writing competition, Sidony Redruth is sent by her editor to write the first-ever travel book on Hy Brasil, a near-mythical island somewhere in the Atlantic, whose very existence has been a matter of debate as late as the nineteenth century. Elphinstone's plot takes the island location as its starting point, throws in some old-fashioned piracy - a lost treasure, modern-day drug smuggling - political intrigue, an active volcano and a tragic love affair.