King of Demons - At Lucifer's Request

Hannah lives a completely ordinary and peaceful life. That is, until the moment her best friend vanishes without a trace from a hotel in Las Vegas. To find her, Hannah seeks out the only man who can help her. Lucas Ifer, a billionaire, playboy, and devil all in one, is the king of Las Vegas. In return, however, he wants something from Hannah – to spend seven nights of sin with him.
Hannah knows she should refuse, but once you make a deal with the devil, there's no turning back. From now on, her body belongs to Lucas, and what's worse – so does her soul.