A missed flight… a lack of intimacy… guarded secrets… To Catherine (Julianne Moore), every detail suggests that her husband David (Liam Neeson) has been unfaithful. But there's only one way to know for sure. Catherine pays the mysterious Chloe (Amanda Seyfried), an escort, to seduce her husband. She wants to know exactly how far she can trust him. But soon Catherine finds herself pushed beyond all limits as passions burn and obsessions build.