Born in 1877, Isabelle (who surfaced briefly in Lesley Blanch's The Wilder Shores of Love--not acknowledged here as one of the bona fide sources) was the fifth child of a woman of means and her lover, a lapsed Pope of the Russian Orthodox Church. They emigrated to Geneva where this neurasthenic family were confined in their home by the stony-hearted ex-Pope, ""Vava."" Isabelle, in the men's clothes Vava dressed her in for security, later escaped to Algiers where she appeared in a burnoose and fez, beginning the years of drifting back and forth from the Continent, across the Sahara, and toward some dual ideal of freedom and mystic identification. She was accepted by a special Moslem tribe, confident that she would become one of their secret saints; always of uncertain status, she was at one point attacked, notoriously tried, and expelled from Algeria (but retained her access by marrying a very dependent Spahi soldier); she sketched, lectured, and kept many diaries, used here along with recently retrieved materials. Cecily Mackworth, an experienced writer, has retraced her steps both in fact and in word with tasteful and finely attuned sympathy.