Joanna (Academy Award nominee Keira Knightley) and Michael Reed (Sam Worthington) are seven years into a loyal and healthy marriage, both balancing challenging but rewarding careers, and enjoying what the city has to offer. One night when the Reeds attend a company party, Joanna witnesses an exchange of glances between her husband and a sexy colleague, Laura (the smart and seductive Eva Mendes), whom Michael never mentioned before. Suspicion mounts when Michael heads out on a business trip with the attractive co-worker in tow. As Joanna begins to doubt Michael's intentions, she finds herself facing her own temptation when her ex-lover Alex (the handsome Guillaume Canet) resurfaces.