The book 'The Yezidis: A Study in Survival' by John S. Guest explores the survival of the Yezidis, a small community in the Middle East, in the face of cultural assimilation. The Yezidis were often dismissed as devil-worshipping troublemakers by their nominal rulers and were outlaws. The book delves into the mystery of how this small group managed to survive despite the constant challenges and threats they faced.