In her role as a spinner of tales, Daphne du Maurier has few equals, and this, which in any other hands would be a fantastically unbelievable yarn, holds the spellbound reader with a mounting conviction that so it might have been. There is more than usual of plot, intricate, many faceted, reaching back into a past that the reader discovers along with John, English professor of 16th century French history, single, bored with his lot -- and thrust by a strange chance into another's life. There is less of atmosphere, though bit by bit you soak up the feel of the provincial French countryside, the rundown Chateau, not far from Le Mans, the village whose people work at the de Gue glass works. And the unbelievable situation she makes one believe? That John encounters by chance, his alter ego, identical externally, Jean, Conte de Gue, who is as eager to escape his role in life as is his English counterpart. But Jean is unscrupulous, cynically amused to bring it about. He drugs the Englishman, takes him to a shady hotel room, there divests him of every shred of proof of identity other than Conte de Gue, orders Gaston, the chauffeur, to collect him in Le Mans the next morning -- and departs, to carry out his side of the masquerade. John, now Jean de Gue, is caught in the net. He finds himself saddled with a gross distortion of a mother, the ancient Comtesse, now brought low by drugs; with a wife, pregnant, terrified that she will not bear the son that will bring the Chateau and the works new life through an inheritance; with a nine year old daughter, who adores her father, and is fearful that a brother will displace her; with a sister, carrying a fifteen year grudge for the death of her fiance, charged as being a collaborator; with a brother, who inadequately carries the burden of the factory on unwilling shoulders; with a sister-in-law who is interested only in prolonging an affaire, and with a mistress in the village who can take it or leave it, as suits her lover's whim. How be meets the multiple problems, the gaffes he inevitably makes, the narrow margin by which he escapes detection, the changes he brings about in the intricate web of lives - to expound further along these lines would betray Miss du Maurier in the fascinating development of her theme. Flawless craftsman that she is, here, is a story that finds her at peak performance. A sure best seller.