This book by P.D. Ouspensky is an invaluable source for studying and understanding the mystical and developmental ideas of G.I. Gurdjieff. Originally and probably better titled "Fragments of an Unknown Teaching" this book was Ouspensky's account of meeting Gurdjieff and becoming part of a group he began teaching in Tsarist Russia, the dissemination and development of his ideas, and their eventual escape from their war torn Bolshevik home.