When the ladies reunite, Lydia is in the hot seat and taken to task for her strong Christian beliefs. Vicki gives an update on her relationship with Steve, while Kelly and Shannon open up about their rocky marriages.
Vicki surprises her son Michael with a new role at Coto Financial; Kelly complains to her mother that she's finally at a breaking point in her marriage; Tamra fulfills her greatest wish of attending her estranged daughter's high school graduation; the ladies celebrate the launch of Meghan's new candle line; and Peggy finally comes face-to-face with all the women after her sudden departure in Iceland.
Peggy reveals a secret video to Lydia after being hurt by Kelly. The ladies eat at a Viking dinner where Vicki and Tamra get along well, dismaying Shannon. Peggy's preemptive strike on Meghan backfires upon arriving at the dinner. Upon returning to the OC, Shannon found the nature of her unbalanced behavior, and that her marriage is on thin ice.
Vicki's health scare continues and brings out a side of Peggy that shocks the ladies. Later, a broken friendship might finally be on the path to mending, while a drunken night causes fractures in another.
Vicki visits her cardiologist. Shanon and Peggy are still simmering about the cancer questioning that took place with their husbands. Lydia and Doug plan an Iceland trip and Doug encourages Lydia to invite her friends to Meghan's dinner party.
Vicki and Tamra finally come face-to-face to see if there is any hope of redeeming their broken friendship. Lydia discovers the joys of when the rich get richer. Kelly's dad comes to town and she discovers the parallels between her parent's dysfunctional relationship and her own. Peggy and Diko celebrate their 22nd wedding anniversary with the ultimate Armenian inspired party while Shannon faces the consequences of her prying husband's actions.
In spite of her hurt feelings, Lydia invites everyone to Doug's party; David questions Diko about her health; Shannon asks her mother for advice about her marriage; Vicki decides to meet with Tamra to end their feud.
Kelly goes into her breast reduction surgery with the sentimental support of her husband Michael. Tamra shares with Meghan her concern over Shannon's recent behavior. Vicki and Shannon visit Kelly while she recovers at home. Shannon invites Tamra, Meghan, Kelly and Peggy out to dinner where Peggy defiantly defeats a deluge of digs from Kelly. And later, Lydia calls Tamra to invite her to Doug's Balls Voyage party, but finds out that her invite to Shannon's dinner was apparently lost at sea.
As rumors swirl following Vicki's birthday party, Tamra catches wind of what transpired. Lydia is perplexed by Vicki's motives and is nervous because of all the women converging at Kelly's party. Kelly is having a breast reduction and decides to have a "Boobs Voyage Party" with all the women except Meghan. Trouble starts at Kelly's party when Tamra and Vicki finally talk face-to-face.
Meghan is still reeling from Kelly's attack. Lydia tries to play mediator but is unable to stay impartial. Tamra gets an unexpected phone call that leaves her wondering about her and Vicki. Peggy prepares to send her daughters off to college. Shannon celebrates her birthday. Vicki throws a party, and an old friend reveals some details about Eddie's past.
Kelly suspects Shannon of being up to her old tricks and confides in Meghan, which blows up when Meghan takes matters into her own hands. Meghan investigates Vicki's issues with Shannon and Tamra. Vicki's looking to move forward with Steve, while Peggy takes her daughter to New York to look at a school. The ladies attend a Drag Bingo event dressed as men, where Lydia faces a moral dilemma and old arguments spark anew as Kelly and Meghan tear into old wounds.
Vicki turns green with envy after learning that Kelly is celebrating St. Patrick's Day with Shannon and Meghan. Lydia wonders if her son's prophecy will come true as she competes in a race. Meghan, Shannon, and Kelly indulge in whiskey and whimsy.
Tamra struggles with broken family issues and her mom's poor communication skills. Lydia hopes Vicki and Tamra can agree to get along, but problems arise when Tamra thinks Peggy is overstepping her bounds.
Vicki tries to balance her life alongside her relationship with Steve; Lydia plans a launch party for her new magazine; Tamra organizes a sit down for Kelly and Shannon; and Megan hosts a Sip-N-See for baby Aspen.
Tamra and Shannon come face to face with Meghan's new baby; Lydia's family takes a vacation full of uncomfortable conversations; Vicki meddles in her son's love life; and Peggy invites her friends to the unveiling of her Lamborghini.
While the fallout from The Quiet Woman leaves Shannon and Kelly both stunned, the ladies move on with their lives as Shannon takes her daughter Sophie out for a driving lesson and Kelly looks to improve her love life from the inside out. Also spotlighted: Lydia's mom throws a birthday party for her grandson, where Vicki forms an instant bond with new housewife Peggy; and Tamra looks to break the cycle of parental alienation and divorce in her family.
Trust issues plague Vicki as she organizes her new office. Also, Peggy deals with her looming surgery; Tamra is thrust back into a past role; and Shannon confronts her weight gain as well as her nemesis, Kelly Dodd, who crashes dinner.
Vicki preps for her office move as Shannon enlists a feng-shui expert to bring balance into her life. Also: Lydia launches her magazine; Kelly tries to make her marriage work; and Tamra hosts an over-the-top birthday bash, where Lydia and Shannon clash.
Vicki expands her business and Tamra reunites with a friend in the Season 12 premiere. Also: Shannon struggles with her weight and her marriage; Kelly worries about her mother; Meghan returns to the O.C.; and Lydia tries to reconnect Tamra and Vicki.