Change is in the air in the OC as Shannon, Gina and Kelly have new significant others and homes. As Shannon takes a tour of Gina’s new house, she vents frustrations about Kelly. Braunwyn and Kelly head to their friend Elizabeth’s beach house and are shocked by Elizabeth’s unconventional relationship. Meanwhile Emily, with a new hip and outlook on life, celebrates her anniversary with Shane. Braunwyn convinces soon-to-be neighbors Shannon and Kelly to meet up and hash out their differences. Later, Braunwyn invites Emily over and shares a secret she has been keeping.

Kelly is focused on her future with fiancé Rick, but wonders how long her recently brokered peace with Shannon will last. Elizabeth and Jimmy bond over their shared Mexican heritage. Braunwyn struggles with her identity and worries that her friends won’t stick around now that she’s not “fun” anymore. Gina reveals that she heard Braunwyn made fun of her “small house” but it turns out she isn’t the only one making disparaging remarks. Gina also brings up the awkward text messages she had with Sean last year. When Emily calls Braunwyn to clarify, she refuses to discuss over the phone. Later, when rumors start to spread, Braunwyn is forced to reveal a secret to Shannon.

Shannon’s got a new house, boyfriend, body, and revamped food line to celebrate and is ready to show it all off at her housewarming party. Emily is hopeful that she can finally make peace with Shannon. Kelly and Gina question Elizabeth’s romantic relationship. Meanwhile, Gina confronts Braunwyn and Shannon about the comments they made about her new home.

Shannon's housewarming party continues; Braunwyn attempts to reconcile with Gina; After Braunwyn leaves, the ladies bond over some tequila shots; Kelly can't wait for Rick to be transferred from New York and move to California full-time.

After her explosive meltdown at Shannon’s housewarming party, Braunwyn finds herself trying to make amends and move forward. Meanwhile, Elizabeth struggles to process her sister’s issues. Gina deals with the next steps in the case against her ex-husband and struggles balancing that with their co-parenting relationship.

As coronavirus makes its way to California, Shannon stocks up on supplies, and Kelly gets bad news.

Braunwyn's vow renewal celebration continues; Shannon and Kelly can't come to an understanding; Shannon offers an olive branch to Braunwyn; Gina decides to stay sober to support Braunwyn; the ladies question Elizabeth's relationship with Jimmy

On their last day in Palm Springs, Gina, Emily and Shannon are busy trying to untangle Elizabeth's ever-changing stories

The ladies begin to self-document their lives during the mandated lockdown due to the global pandemic. Elizabeth has a change of heart about her divorce proceedings, Emily and Shane’s relationship takes a turn, and Kelly travels across the country to be with her fiancé, Rick. When tension arises between Shannon and John, Gina gives her two cents. Meanwhile, Braunwyn struggles to keep her sobriety and marriage intact during the quarantine stress. And as Braunwyn digs into Elizabeth’s past, Elizabeth invites the ladies for a bonding trip in Lake Arrowhead and Shannon receives some shocking news.

Elizabeth plans a getaway trip to Lake Arrowhead for the ladies, but not everyone is able to make it because of health concerns. On her continued journey to sobriety, Brauwnyn struggles to find her new normal amongst the group and in her marriage. The women enjoy a day on the lake before having a controversial discussion on the Black Lives Matter movement and racial inequality in America.

On the second day of the trip in Lake Arrowhead, Gina receives emotional news while Braunwyn and Elizabeth face off about Braunwyn investigating her past. After some fresh air and outdoor activities, Elizabeth makes a shocking revelation. Back in the OC, Shannon gets devastating news and Emily struggles to keep it together for her kids while Shane is in the hospital.

As the ladies continue to enjoy their getaway in Lake Arrowhead, Gina and Kelly attempt fly fishing while Elizabeth discloses her deepest, darkest secrets to Braunwyn. Back in the OC, Shannon calls the ladies with surprising news and Emily welcomes home Shane from the hospital. Braunwyn struggles with the state of her marriage, and Kelly, Rick and Jolie settle into suburban life.

With the group back in the OC, Shannon preps her oldest daughter Sophie for college while Emily reveals a surprising rumor. As Braunwyn and Sean discuss their marriage problems, Shannon and John work through their issues from quarantine, but she fears the damage has been done. Later, Elizabeth opens up about her past to Emily, and Kelly questions Braunwyn’s authenticity.

The ladies get together for the first time in months when Emily throws an elegant beach party. But with a lot of unfinished business in the group, the gloves quickly come off. Gina is shocked to learn Shannon is holding a grudge against her and Braunwyn struggles with evolving feelings in her relationships. Later, Elizabeth takes steps to heal the wounds from her past, and Kelly confronts Braunwyn about her authenticity

The reunion begins with Shannon on defense regarding the disparaging comments surrounding Gina’s new home and her involvement in digging into Elizabeth’s past. Tensions flare when Kelly and Emily call out Braunwyn for deflecting when she makes an accusation about Shannon. Andy presses Kelly about her controversial comments surrounding the pandemic, and Emily gets emotional about Shane and their experience with COVID-19. Braunwyn reveals a surprising connection to Elizabeth’s past leading to an explosive confrontation. Emotions run high when Shannon reveals Braunwyn’s involvement in a serious incident with her daughter.

In part two of the reunion, Braunwyn struggles to come to terms with her past behavior involving Shannon’s daughter. Gina shares an update on her relationship with Travis. Andy questions Kelly about her social media posts, while the ladies confront Braunwyn about her authenticity. Elizabeth opens up about growing up in a cult. Sean joins the ladies to discuss Braunwyn, their modern marriage and their future. The ladies close out the season with a toast and share what they learned from the most challenging year that tested their friendships and relationships.