Perfect wives， imperfect lives， and upending the rules of behavior in 1960s America。

Law school graduate and newlywed Ruth Applebaum is acclimating to life and marriage in a posh Philadelphia neighborhood。 She’ll do almost anything to endear herself to her mother-in-law， who’s already signed up Ruth for etiquette lessons conducted by the impeccably accessorized tutor Lillian Diamond。 But Ruth brings something fresh to the small circle of housewives—sharp wit， honesty， and an independent streak that won’t be compromised。

Right away Ruth develops a friendship with the shy Carrie Blum。 When Carrie divulges a dark and disturbing secret lurking beneath her seemingly perfect life， Ruth invites Lillian and the Diamond Girls of the etiquette school to finally question the status quo。

Together they form an unbreakable bond and stretch well beyond their comfort zones。 For once， they’ll challenge what others expect from them， discover what they expect from themselves， and do whatever it takes to protect one of their own—fine manners be damned。