To the Devil a Daughter by Dennis Wheatley
Why did the solitary girl leave her rented house on the French Riviera only for short walks at night? Why was she so frightened? Why did animals shrink away from her? The girl herself didn't know, and was certainly not aware of the terrible appointment which had been made for her long ago and was now drawing close. Molly Fountain, the tough-minded Englishwoman living next door, was determined to find the answer. She sent for a wartime secret service colleague to come and help. What they discovered was horrifying beyond anything they could have imagined. Dennis Wheatley returned in this book to his black magic theme which he had made so much his own with his famous best seller The Devil Rides Out. In the cumulative shock of its revelations, the use of arcane knowledge, the mounting suspense and acceleration to a fearful climax, he out-does even that earlier achievement. This is, by any standards, a terrific story.