The Flagstone Path

The main character, Rachel, tells the story of meeting a childhood friend, Jenny. With Jenny, Rachel encounters Jenny''s grandpa who molested her.
What began as normal curiosity about the human body quickly turned into a gripping fear of being found out. For Rachel, this fear went along with a quiet self-loathing for her own sexual response to the molestation.
Jenny mysteriously vanishes after Rachel witnesses her being tortured by her grandma. Rachel finds Jenny again, thirty years later, in a bizarre situation.