While Vicki revels in the return of her family to Orange County, Heather strives to find a work/life balance on the eve of her book launch. Kelly struggles to figure out Shannon's motive for setting her up and bonds with Vicki over their shared anger. Tamra plans a last hurrah for Meghan before she gets pregnant, but the sushi party goes off the rails when Kelly loses her cool and crosses a line.

In the season 12 opener, old feuds are still hot topics among Vicki, Kelly, Shannon and Tamra, with battle lines clearly drawn in the sand. While awaiting apologies that aren't forthcoming, Vicki is busy expanding her business and moving offices, Tamra is reuniting with an old friend who shares her faith, while Shannon struggles with her weight and her marriage. Kelly's concerned her mother's becoming a hermit and Meghan is making her way back to Orange County after the birth of her baby, Aspen. Returning housewife Lydia, now a mother of three, is determined to bring Tamra and Vicki back together but soon realizes she may be in way over her head.

Vicki prepares for her big office move while Shannon enlists the help of her feng shui expert to try and bring balance into her otherwise chaotic life. Lydia is busy launching her brand new magazine which features Peggy, an Armenian firecracker, whose life may look perfect but not everything that glitters is gold. Kelly struggles to make her marriage work while Meghan settles into life as a new mom. Tamra plans an over-the-top birthday party for her granddaughter, Ava, where tempers fly as Lydia and Shannon meet for the first time and don't see eye to eye when it comes to Vicki.