Retribution by Lietha Wards

Ryan Casey was hired as a bodyguard by a drug lord to protect his daughter after a kidnapping left her sister dead and her beaten. He was there to do a job and if she was going to resist, he would bring her to heel so he could get it done. He didn't care about her or her father, because he had another reason for infiltrating the organization. One that made him blind to the innocents he could hurt.
Katya Nickolov was innocent. In fact, she was completely naïve of her father's dirty business until her captors revealed it to her. Then they inexplicably released her leaving her no place to go except back to a man she despised; her father. Furthermore, he hired a man who she didn’t know, to protect her. He was arrogant, demanding and unforgiving. Worst of all, he commanded her to obey him without question. This was something she refused to accept.
Soon they discovered that they weren’t so different after all, and Katya had to make a choice between her family and the man who swore to destroy them.