Captive in the Cloister of Lust: Passion and Humiliation #3
C.P. Waterman, Chera Zade

Having escaped the clutches of her lecherous kinsfolk, Caroline Ashton now lives in comfortable surroundings… until fate brings her back to the misery of the Hall of Lust once more. But her return there is short-lived; she is despatched to a nunnery in France where the establishment soon reveals itself to be a sordid den of female debauchery. And what of the strange Sister Barbara… she can't really be a woman, can she...?
Without money, without friends, and without hope, how will she ever return to England now?
(This episode - at over 20,000 words long - is almost the length of a novella)