Just who is the villan here?

Pity poor single mom Louise. She goes out for a night at the pub and engages in a little flirtation and kissing with a hot guy.  Soon afterwards, he's introduced as her new boss. AWK-ward!  Unfortunately, things rapidly get more complicated that even that situation would suggest in the new novel Behind Her Eyes.

Louise's ex-husband has been remarkably generous.  He continues to pay most of her bills and participates in the shared custody of their son, even though he's remarried.  This allows Louise to live in London (although in a small apartment) and only work part-time as a secretary for a psychiatrist.  Once David, her pub guy, joins the practice they quickly rekindle their relationship.  Of course, it's not long before Louise is able to confirm her suspicion that David is married.  His wife is willowy, blonde and beautiful.  Soon after she takes up with David, Louise is nearly knocked down when a woman runs into her (literally) outside her son's school. Improbably, David's wife, Adele, has collided with her.  To apologize for their mishap, Adele suggests they go for a coffee.  Louise admits that she is David's secretary, and while the two women enjoy a nice chat, Adele asks that Louise not mention their meeting to David.  The two women hit it off and are soon seeing more of each other, even going to the gym together.  All this puts Louise into an odd position:  she's having an affair with her new bestie's husband, but he has no idea the two women know each other.

The chapters alternate between Adele's past and present, as well as shifting the present narrator from Adele to Louise.  When Adele was a teenager, David (whom she'd always had a crush on) rescued her from a fire that killed her parents.  Although the death of her parents left her wealthy, Adele was unable to cope with the tragic events and spent some time at a rehabilitation center/hospital where she met recovering addict Rob.  Even though she's in love with David, she knows he'll get along well with her new best friend Rob once they meet . . . but is she being overly optimistic?

As present events unfold, Louise becomes increasingly suspicious of David.  While he appears kind and loving, disturbing events surrounding Adele make her concerned for her new friend.  Why does Adele have to rush home to take David's calls at a certain time every day?  Why does she take so many prescription medications?  And what about those bruises on her face?  Could David really be dangerous?

Events become more and more nail-biting as we grow more concerned for Adele (is she in danger from David?) and Louise (ditto?).  Could the events that happened during the deaths of Adele's parents have something to do with why she and David are locked in an uneasy marriage?  As is being mentioned, there is a final twist that will surely hit the reader out of the blue (it did me!).  If you like to unravel a mystery and be hit with a shock ending, this is the book for you!

Disclaimer:  I received an Advanced Reading Copy of Behind Her Eyes from Flatiron Books in exchange for this review