Alright, this is another in the "Dark Erotica" series, which oddly enough is not terribly dark.
Mia was abused as a child/young lady, ran away from home, was taken in by a gangster and turned into his slut/whore. So far, pretty dark, I'll grant you.
Then her next door neighbor shows up, and joins the gang. Mia is offered to him, forced into acts of depravity and beaten. Good so far!
Then we go off the rails, as we often seem to in this series, and Mia escapes with Tyler, who it turns out was her true love all along, and he rescues her from all the bad men and carries her off to marriage and happily ever after.
So yeah, another intriguing premise with execution that landed it in happy go fluffy land.