The ladies of New York are back after an eventful summer. Newly divorced Luann sits down with Dorinda and starts to open up about her relationship with Tom. Meanwhile, Bethenny mourns an unexpected death in the family. Typically reluctant to exercise, Carole preps to run the New York City Marathon. All the ladies reunite when Dorinda throws an epic Halloween party that nobody will forget.

Sonja makes hurtful accusations about Tinsley's finances; Dorinda attempts to improve her friendship with Sonja; Carole runs the New York City Marathon after months of training, but with a surprising omission in her cheering section.

The ladies head to the Hamptons for a fun-filled weekend; tensions rise between best friends Carole and Bethenny; Dorinda and Sonja's friendship is short-lived, as a blowup at Luann's brunch sets their relationship back.

Tensions boil over between Dorinda and Sonja at Luann's brunch; at Ramona's dinner party, Tinsley delivers a low blow to Sonja that shocks the whole party; Sonja calls out Ramona for not being a true friend in a text message.

Back in New York City, Tinsley gets a surprise delivery; Carole and Luann talk through the miscommunications that have been plaguing their friendship; Luann runs into Tom's old fling; a shouting match erupts between Sonja and Ramona.

Carole reveals shocking news about her relationship with Adam; Sonja prepares her townhouse; at an important business dinner in Miami with Bethenny's relief team, Dorinda jeopardizes her chances of going to Puerto Rico.

Bethenny and Dorinda hit the ground in Puerto Rico and get to work; Ramona attempts to mend fences with Sonja; Carole works on a revealing story with a magazine; Luann starts to plan a special performance.

The ladies make their annual visit to the Berkshires; Carole confides in Dorinda and Ramona about some tension with Bethenny; the ladies get decked out for a 1920's murder mystery dinner party taking place at Blue Stone Manor.

Carole and Bethenny continue to hash out their issues during the murder mystery dinner party; back in the city, Bethenny's holiday party is interrupted by a surprise, which leads to hurt feelings; Luann gets arrested over the holiday.

Weeks after Luann's arrest, she's still the talk of the town; while she's in rehab, the ladies try to piece together what happened; Bethenny throws a launch party for her jeans line; Sonja flees her construction site and spends a night with Tinsley.

Tinsley tries on wedding dresses with her mother, Dale; while Luann ends her stint in rehab, the women tough it out during a prison-style workout; Bethenny and Jill Zarin share an intimate moment after the funeral for Jill's husband, Bobby.

Luann gets out of rehab and the ladies whisk her away for a spa weekend in Connecticut; the relaxation doesn't last long as Luann discovers that Ramona tried to get an invite to Tom's New Year's Eve party; Dorinda and Sonja clash over a family crest.

Luann deals with unwanted press; Dorinda confronts Bethenny about lingering tension; Bethenny puts Tinsley on the spot over wedding dress shopping; Dorinda's ongoing issues with Sonja reach a fever pitch; Luann confronts Ramona about disloyalty.

Luann prepares for her upcoming cabaret show; Bethenny creates a dating profile for Sonja; Tinsley moves into her new penthouse, without Scott's help; the women attend a speed-dating event; the ladies decide to go on a trip to Cartegena, Colombia.

The women arrive in Cartegena, Colombia, for their vacation; Bethenny has an allergic reaction; Luann reveals a shocking new look; an injured Ramona gets wheeled around the cobblestone streets. Bethenny clashes with Dorinda and Carole.

As the ladies head out to shop in Cartegena, Bethenny continues to unravel, and the women's patience with her begins to run out; Carole approaches Sonja for insight on Bethenny; a comment Luann makes to Dorinda sends Dorinda off the deep end.

Tensions arise at breakfast as Luann and Dorinda continue their argument from the night before; the ladies ditch the city for a private island; the day ends with a traumatic boat ride as the women are rushed off the island.

Ramona shows off her newly renovated Hamptons home; Sonja stands firm on the asking price for her townhouse; Bethenny invites Dorinda to her new apartment; Adam shows up bearing gifts at Carole's athletic-chic Cosmopolitan Magazine party.

It's the night of Luann's cabaret show, "Countess and Friends"; during the performance, Luann gets heckled, and Sonja shows some skin; at the after party, Ramona has a burning question for Bethenny, while Dorinda has some parting words for Luann.

The ladies relive some of the fun times they had this season, gathering to discuss the year's events with one glaring absence. The women also pay tribute to Bobby Zarin while questioning Bethenny's motives for attending his funeral. Dorinda confronts questions about her biting tongue, and Bethenny defends herself when a few of the others gang up on her. Finally, everyone gets a lesson in graciousness from Dorinda, and they take a look back at some of their questionable wardrobe choices.

Dorinda defends herself against accusations that she might have a drinking problem. The ladies discuss Luann’s obvious absence and share their observations of her recent behavior. Tinsley reveals startling details about her relationship with Scott. And Bethenny and Carole dive into what caused the seismic shift in their friendship and call each other out for comments made both on and off the show

Bethenny and Carole continue to discuss the dissolution of their friendship; the women relive their stomach-churning trip to Colombia; Sonja talks about a new chapter in her life; the women share their biggest regrets of the season.