The Comfort of Strangers — Ian McEwan

A twisted relationship between two couples reaches a terrible climax in this novel by the New York Times-bestselling author of Machines Like Me.
 
Colin and Mary are lovers on holiday in Italy, their relationship becoming increasingly problematic as they become increasingly alienated from one and other. They move from place to place in this foreign land but seemingly without aim or purpose, seemingly bored and without attachment. Then they meet a man named Robert and his disabled wife, Caroline.
 
Colin and Mary seem happy for the diversion -- happy to meet another couple that takes their focus off of each other for a while. But things become strange when they attempt to leave: Robert and Caroline insist that they stay with them for a while longer. While Mary and Colin do rediscover an erotic attraction to each other during this time, they also find that their relationship with Robert and Caroline is taking a dreadful and horrific turn, in this “fine novel” by the Booker Prize-winning author of Saturday and On Chesil Beach (New Statesman).
 
“McEwan perfectly captures the thrill of travel when one is divorced from familiar surroundings and the chance of something unusual and out-of-character seems possible. Of course, this being a McEwan fiction, the possibility is a brutal truth about how people find love in extreme ways.” -- The Daily Beast