Excellent story. Unfortunately, I only finished reading it now.
First, I want to praise how realistically, in my opinion, it shows the transformation of an ordinary teenage girl into a completely submissive thing, totally belonging to her Master. How he ruthlessly and cynically got her hooked on love and pleasant sensations, and then destroyed her morally.
Secondly, for the plot to be completely realistic, there should have been some remarks about the surrounding world. The girl lived in society, went to school... I understand that this does not affect the plot, but for complete credibility, it would be interesting, in my opinion, to tell how Peter managed to completely remove Sarah from school so that no one was concerned. Or is it that simple in the US?
Anyway, big thanks to the author.