Though Rachel is a successful attorney and a loyal, generous friend, she is still single. After one drink too many at her 30th-birthday celebration, Rachel unexpectedly falls into bed with her longtime crush, Dex -- who happens to be engaged to her best friend, Darcy. Ramifications of the liaison threaten to destroy the women's lifelong friendship, while Ethan, Rachel's confidant, harbors a potentially explosive secret of his own. Friendships are tested and secrets come to the surface when terminally single Rachel falls for Dex, her best friend Darcy's fiancé.