The Diaries of Syra Bond. Syra: Trained to Obey, #1

Imprisoned by a perverted captor, research student, Syra, is forced to write about the sexual misdeeds that led to her captivity. She tells in explicit detail - and under constant censure and threat of punishment - how, in the heat if a long Spanish summer, her cruel master, Galen, as part of an experiment in control, trains her to complete obedience. She recalls how she fulfils his every wish as, with a mixture of mental control and chastisement, he takes her to the limits of obedience where everything, real and imaginary, becomes part of the sexual world he contrives for her.
Syra's exposure to Galen's cruelty serves only to increase her desire for satisfaction from humiliation. But even though she submits to everything she is told - and there seems nothing that limits her desire for degradation - the final outcome proves to be an ultimate and unforeseen humiliation that sets the scene for the rest of her life.