Still in the Hamptons, LuAnn and her kids get a surprise visit from Rosie who is no longer their housekeeper but is still concerned about the family as a whole. The Singers and the Van Kempens meet for dinner and the subject of a comment Mario made to LuAnn comes up. Bethenny and Jason head out for a romantic dinner and Jason asks Bethenny to move in with him. It's Labor Day weekend and both Ramona and LuAnn decide to throw parties - the issue becomes which party will the ladies go to?

 Ramona kicks off fall in New York City with a rooftop cocktail party. Things are still tense between Jill and Alex as this is the first time they've seen or spoken to each other in months. The newest Housewife Cindy Barshop, owner of Completely Bare spas, is having an art party and all the girls show up, invited by Ramona, Cindy's friend.

 Sonja kicks things off with a party to mingle with Aviva, Carole and Heather. They all seem to hit it off... until Ramona arrives. Heather and Carole try to figure out who to trust and not. Picking up right where they left off, LuAnn is still annoyed with Ramona about the disparaging comments she made about LuAnn's parenting and tries to discuss it with her at the party.

 The ladies are back and fierce as ever. Heather hosts her own birthday party, but no one is looking forward to seeing Aviva after some of her past eyebrow-raising behavior. Aviva approaches Ramona and attempts to bury the hatchet, but will Ramona take the bait? The ladies are also introduced to Heather's longtime friend Kristen, a working model and mother-of-two whose beauty becomes the talk of the party. Later, Aviva continues, in desperation, to get back into Ramona's good graces, but her final efforts prove shocking.