My character was sold to a rich man to help with their debt when she was 18 years old and she was then used as a sex slave and was constantly abused. She lived with this man for 2 years and when she was 20 she was passed on to someone else who did the same thing as well as had passing her around to friends and that went on for 3 more years. So, for 5 straight years she has been constantly abused and made to feel like she is nothing and just not even human. So, now she doesn't speak unless she is given permission.
Well, after her last owner she is left on the streets and after about 3 months someone picks her up and puts her into a slave auction. They knew she was a slave just by the collar since it was different from just a pet/submissive collar. When put into this auction she is cleaned up and given decent clothes but even that couldn't hide the bruising and emotional pain she had known all these years. She has been in this auction for almost a month and no one once her cause she is "used up". Your character heard about the auction and decided to check it out. She is very wealthy as well except she is nothing like the others my character has had in the past. She ends up buying her, takes her home and takes care of her. At first my character thinks she's like the others and barely speaks but as time goes on she grows to love and trust her.