The Dying Wish by Courttia Newland
Ervine James is in incredibly good spirits - his Private Investigation business is going well, he has partially restored his tenuous link with his family, and his best friend of old and new partner Carmen Sinclair has proved to be more of an asset, both emotionally and financially, than he ever could have dreamed. But when a beautiful Asian woman appears outside the office next to his, a mysteriously secretive company rents the space for a few months before suddenly disappearing without trace, followed by arrival of police detectives investigating allegations of organized group homicides, Ervine and Carmen are drawn into a mystery so deep, so calculated in its intentions, neither believe that they could find out the truth behind that office door without risking their very lives...