In Part 3 of the reunion, Heather and Aviva butt heads when Aviva decides to "out" Heather. Ramona tries to dismiss Kristen and her opinions, but the new girl won't be so easily shut down. Ramona and Sonja must defend their relationship. The ladies open up about the individual struggles and heartache they faced this year. Plus, Aviva discusses what led her to throw her leg at Le Cirque and the women reveal more behind-the-scenes of what really happened that night.

In Part 2 of the reunion, tension between Aviva and Carole comes to a head as they unravel the details of the infamous "Bookgate" feud. Ramona digs herself into a deeper hole with Heather when she tries to explain her disdain for the Berkshires. LuAnn confronts Sonja about the decline of their friendship. Things take an unexpected turn when Andy asks Ramona for answers about the status of her marriage. LuAnn takes the opportunity to get even with Ramona for her past comments about LuAnn's divorce.

Hosted by Andy Cohen, the ladies of NYC -- Aviva Drescher, Sonja Morgan, LuAnn de Lesseps, Carole Radziwill, Ramona Singer and Kristen Taekman -- reunite for the first time since the jaw-dropping Season Finale. Ramona is in the hot seat for her behavior towards Kristen in Montana, and Carole confronts Sonja about spreading rumors about her ex. Plus, LuAnn minces no words telling Sonja exactly what she thinks of her and her sometimes questionable headspace.

After being swooned and then ditched at Carole's birthday party, Sonja must confront both Harry and LuAnn about their alleged "night together." Meanwhile, Kristen pulls some matrimonial strings to get a modeling job. Then, when Aviva returns to the group for the first time in weeks -- insults, accusations, and body parts fly in an epic season-ending confrontation.

Carole turns fifty and decides to celebrate her birthday with an extravagant, all-out bash. Ramona and Mario prepare for life in an empty nest as they send daughter Avery off to college, while Kristen and Josh seek professional help to put their marriage back on track. Sonja receives an unexpected piece of jewelry and a promise from Harry Dubin , Aviva's ex, but a shocking turn of events rattles their relationship to the core.

When the girls return from Montana, Aviva learns her illness has been the butt of everyone's jokes and decides she needs a break from the group. Ramona's husband Mario is slated to perform at an open mic night at Birdland, one of NYC's most iconic Jazz bars. Heather and LuAnn are also slated to sing, but when LuAnn backs out, Ramona flies off the handle. Kristen cooks dinner for Josh in an attempt to lure him home on a more regular basis. When he shows up late, a tense argument reveals some deeper problems in their relationship.

Heather and Kristen are still at odds as the ladies prep for their evening of "glamping." Kristen accuses Heather of being bossy and the argument forces some of the ladies to take sides. Surprisingly, Ramona sides with Kristen and they form a bond for the first time. Heather and Kristen can't make up before the big rodeo show where the ladies enjoy an event that brings them totally out of their element. At the final outdoor Montana dinner, the ladies and a posse of cowpokes throw hatchets, while Kristen and Heather convene down by the river to try and bury theirs.

The ladies are halfway into their Montana adventure and tension between Sonja and LuAnn still lingers. There are distractions from the drama with a full day of outdoor activities. The women become true City Slickers when they try their hand at fly fishing, skeet-shooting and repelling, but when it's Kristen's turn to descend down the mountain, things get tense. The ladies come together for a modern day treasure hunt called Geocaching, only to splinter apart again when a beer-lubricated Heather gets on Kristen's last nerve. Old friends Kristen and Heather square off in the most unexpected tiff of the season.

The ladies are set to escape the city and venture into big sky country: Montana! As their departure looms, Aviva and Ramona agree that Montana is not their dream destination. After procuring a doctor's note, Aviva opts out of the trip due to a sudden horse allergy and asthma condition that nobody is buying. The ladies hit the ground running in Montana, strapping on their designer boots and hats before heading out on a real-life cattle drive. Later that night, in a restaurant that doubles as a stable, a peaceful dinner goes awry when LuAnn and Sonja start fighting about gossip spread by the infamous facialist.

Sonja's gossipy facialist spills secrets about the women to Kristen, who shares what she heard with Carole and LuAnn, who angrily refute the stories. LuAnn hosts a charity luncheon where Aviva sends around a naughty text that royally ruffles the Countess' feathers.

Aviva's sex-crazed father, George, has shocking news for Cody, his twenty-five-year-old girlfriend. Aviva decides to throw them a party at a surprising, yet fitting, museum. Can Ramona and George reconcile or will their dislike for each other ruin the night? LuAnn takes everyone but Aviva and Ramona to Saratoga for a weekend of horse racing, drinking, and man chasing, but Sonja parties a little too hard and things quickly get out of hand.

Aviva's controversial father, George, returns, and this time, he has a surprise in the form of a new lady friend. Everyone gathers to bid Sonja's dog adieu in a memorial like no other.

Back in New York City, the women confront Ramona about her bad behavior, specifically, ditching them for a party in the Hamptons. LuAnn invites Carole on a double date, but will Carole's awkward dating behavior end it before it begins? In a last ditch attempt for reconciliation, Ramona apologizes to Kristen, but Kristen may not be ready to forgive.

Heather attempts to calm the quarreling Kristen and Ramona with a dinner fit for a King. The next morning, the women are hiking in the woods when Ramona stumbles upon something that brings out her worst childhood horrors, causing her to flee the Berkshires. Then, the ladies enjoy a relaxing afternoon of sunbathing, swimming, and hitting on young men before a final dinner out where they devise a plan to give Ramona her "just desserts" for abandoning them under suspicious circumstances.

Heather invites all the ladies, except Aviva, to her vacation house in the Berkshires for the weekend. Things get dangerously out of hand when a placid canoe trip turns into a blood bath, with Kristen and Ramona going head-to-head.

After standing Sonja up for a sunbathing date, Ramona decides to spill Sonja's financial secrets all over the Hamptons. Meanwhile, back in New York, Kristen meets with a new modeling agent, and is shocked to learn that her modeling days may be over. When Sonja is stood up by her 23-year-old boy toy, she suspects that Ramona had something to do with it.

It's the Fourth of July weekend in the Hamptons, and the women gather for some fun at the beach. Kristen and Ramona butt heads over Ramona avoiding Heather's anniversary party. The tension sets the mood for the rest of the weekend.

Ramona is back from her family trip to Africa and she's collected a new-found inner peace. Kristen and Carole meet their old friends Brandi and Yolanda from The Real Housewives of Beverly Hills. Heather and Jonathan host a 10-year anniversary party, but when Heather finds out that some of her "friends" decided to boycott the event, a tempest of anger forms.

A rare honor is bestowed upon Carole at the Coney Island Mermaid Parade, which leads to Carole, Kristen, Sonja, LuAnn and Heather cavorting around the boardwalk dressed as sea-going drag queens. Meanwhile, Aviva and Reid head Upstate to see if Aviva can face her biggest fear -- the very machine that took her leg when she was a child.

The women head to the Hamptons to watch Sonja perform a burlesque number at a charity event. Countess LuAnn makes her return to the group as she hosts a Hamptons barbecue at her home, where another explosive argument regarding "BookGate" leads Heather to ferociously defend Carole.

Carole and Aviva's explosive fight at Aviva's housewarming spills out into the party, shocking all in attendance. Kristen gets pressure from her husband and Heather to run in a brutally physical mud run. Will she make it to the finish line with her body -- and marriage -- still intact?

When Aviva scores a book deal for her memoir, she decides to meet with Carole, the renowned author of the group, for help. Their lunch quickly turns uncomfortable and things get ugly when the topic of "ghostwriters" is mentioned. Aviva hosts a housewarming at her new Upper West Side townhouse where Ramona sets Carole off by spreading some damning gossip.

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. The ladies are also introduced to Heather's longtime friend Kristen, a working model and mother-of-two.