It is Lisbon in the year 1905 and our hero, Luis Bernardo Valenca, owner of a small shipping business, is revelling in the luxury of Lisbon's high society. But his life is turned upside down when King Dom Carlos asks him to become governor of Portugal's smallest colony, the tiny island of Sao Tome e Principe, whose economy rests almost entirely on its cocoa plantations. The English believe that slavery still exists illegally in Sao Tome and intend to send a diplomatic envoy to check it out.

This book traces the early-twentieth-century journey of the Englishman Joseph Burtt to the Portuguese colony of Sao Tome and Principe-the chocolate islands-through Angola and Mozambique, and finally to British Southern Africa. Burtt spent six months on Sao Tome and Principe and a year in Angola. His five-month march across Angola in 1906 took him from innocence and credulity to outrage and activism and ultimately helped change labor recruiting practices in colonial Africa.