Tears of Tess question

There was a book where the girl & her boyfriend were on a date and the giy suddenly left to go to the bathroom. While he was there, the girl was abducted. She was then sold to the black market. While on the market, she was sold to a kind man. The man himself lived in this closed community where the men were abusive and the women were treated as slaves. The man and the woman got married & over time began to fall in love. They also started plotting to free other women from that community.