Well … A very interesting premise.

The Guest Room is a 2016 psychological thriller novel by Chris Bohjalian. 

• The Party: Richard Chapman agrees to host a bachelor party for his younger brother at his upscale Westchester home while his wife, Kristin, and daughter are away. 
• The Incident: The party turns violent when two young women, who were brought there by force as sex slaves, kill their Russian bodyguards and flee into the night.
• The Fallout: Richard’s home becomes a crime scene, he is placed on indefinite leave from his investment banking firm, and his marriage falls apart because of a brief, intimate encounter he shared with one of the women in his guest room. 
• The Escape: The story shifts between Richard trying to salvage his life and Alexandra (Anahit), a 19-year-old Armenian woman running from both the police and the deadly Russian mob. 

The book provides a look at the violence and degradation associated with modern global sex slavery.

I found the ending a surprise. And shocking.