The Prophet of Yonwood is an apocalyptic science fiction novel by Jeanne DuPrau that was published in 2006. It is the third "Book of Ember" of the series, and a prequel to The City of Ember. It is set about fifty years before the Disaster and the establishment of Ember, and approximately three hundred years before the events of The City of Ember, The People of Sparks and The Diamond of Darkhold.