The Other Sister by Sarah Zettel.
What's it about? From Grand Central Publishing:
"Two sisters. One murder plan.
Everyone thought reckless, troubled Geraldine Monroe was the bad sister - especially when she fled town after her mother's death twenty-five years ago.
But people don't know the truth.
Marie Monroe knows. She was there for their father's cruel punishments, the constant manipulation, the lies. Everyone thinks she's the perfect daughter - patient and kind, and above all obedient. No one would suspect her of anything. Especially not murder.
Now Geraldine's home again, and she and Marie have united in a plan for the ultimate revenge. But when old secrets and new fears clash, everyone is pushed to the breaking point... and the sisters will learn that they can't trust anyone - not even each other.
An intense psychological thriller full of family secrets, perfect for readers of The Woman in the Window and Watch Me Disappear." Read or listen to an excerpt here.
"Sarah Zettel is an award-winning author. She has written eighteen novels and multiple short stories over the past seventeen years in addition to practicing tai chi, learning to fiddle, marrying a rocket scientist and raising a rapidly growing son." You can connect with Sarah Zettel on her website, like her on Facebook and follow her on Twitter.
And if you'd like to read The Other Sister, enter for a chance to win a copy using the Rafflecopter form below. Open to US and Canada, no PO boxes please. Ends Sept.1/18.