In the Season Four premiere, Lisa Vanderpump vows to take SUR restaurant to new heights. Scheana throws a party for her 30th birthday, but when Kristen shows up, Ariana and Sandoval accuse Scheana of being a fake friend. Schwartz realizes he's ready to commit to Katie, and a visit from Jax's mother offers insight into his life before SUR.
When Lisa Vanderpump brings new blood to the shark-infested waters of SUR, Katie and Scheana quickly teach new girl Lala that there's no such thing as a secret at Lisa's restaurant. Rumors spread that James was unfaithful to Kristen, and Kristen must make a tough choice about who to believe. Jax imports a new girlfriend from Kentucky and Scheana continues to feel the heat from Ariana over her friendship with Kristen.
Scheana and Katie bust new employee Lala for lying about a modeling job in Italy; Jax and James compete for Lala's attentions; Scheana discovers her husband has been keeping secrets; Tom Schwartz takes a big step in the direction of commitment.
Lisa Vanderpump and the SUR crew force Scheana to reassess her marriage now that Shay's secret life is out in the open. Jax campaigns to get his new flame a job at SUR, even while things heat up between him and Lala. Sandoval and Schwartz pitch Lisa a business plan. Kristen and James seek couple's therapy.
Convinced that Kristen is cheating on him, James seeks revenge by hooking up with Lala. Katie and Ariana urge Scheana not to sweep marital problems under the rug, and a jealous Jax recruits Kristen in his scheme to pull Lala away from James.
Lisa invites a group of underprivileged children to SUR, which includes a serving of bad behavior on the part of her staff; Jax stands up for Kristen after her breakup turns ugly; Tom Schwartz and Tom Sandoval's business plan fails to impress.
Lisa advises the women to get back at their boyfriends for going to Las Vegas, so Lala, Katie and Ariana kiss and make up at Scheana's sleepover; Jax, Schwartz and Sandoval strive to remain loyal to their girlfriends while in Sin City.
Tom Sandoval and Tom Schwartz divulge shocking news about their trip to Las Vegas; Kristen returns to SUR, but Ariana is not ready to forgive; Tom Sandoval and Ariana take the stage at the Improv; James tries to sabotage Jax's love life.
Tom Schwartz plans on going down on one knee to propose to Katie, but Lisa frets that his complicated scheme will end in disaster; Brittany moves in with Jax; Kristen and James get left out in the cold when the SUR crew plans a tropical vacation.
The SUR gang travels to Hawaii to celebrate Jax and Tom's birthdays, bringing their conflicts with them. Lala tries to come clean about her flirtation with Jax, but Jax refuses to accept any blame. Tom discovers Scheana sent negative texts about him to Ariana's mom. Katie lashes out when Lala skinny dips in front of Schwartz, and Lisa Vanderpump frets over Max from 3,000 miles away.
While the SUR crew parties in Hawaii, Stassi visits Kristen and reveals the truth about her sex tape. Ariana rejects Scheana's fake apologies, and Tom strikes back with an attack on Scheana's marriage. Lala kicks James out of bed for an equipment malfunction, and just hours before leaving paradise, Jax winds up in jail.
Accused of felony shoplifting, Jax must answer to the courts, his girlfriend, and – worst of all – Lisa Vanderpump. Stassi finally tells the whole story of her sex tape crisis, and returns to SUR to repay Lisa for helping her keep the tape from leaking. James and Lala can't keep their hands off each other at a racy photoshoot, Scheana and Shay toast the end of a rocky first year of marriage, and Kristen deals with a "Stage 5 Clinger" boyfriend.
Katie stats her Web site with a party, but a surprise appearance by James and a text message from Stassi could end up threatening to ruin the event.