After a wild (and rumor-filled) weekend in Miami, Kristin swings by Audrinas place to invite her to a barbecue -- and find out what she thinks about rumors of Kristin's out-of-control partying. Audrina says she plans to bring her new boyfriend, singer Ryan Cabrera, but when she asks if Stephanie and Lo are on the guest list, Kristin admits she suspects them of spreading lies about her in Miami. Audrina admits she doesn't know who started the rumors, but says Lo and Stephanie might've gotten confused when Kristin stood them up to go partying with Stacie. Unconvinced, Kristin hints that the girls didn't waste any time jumping to conclusions and points out that "anytime there's a problem, Stephanie's involved." Kristin resolves to "get to the bottom of this and end this."Meanwhile, Lo and Stephanie are driving around when Lo receives a report about Kristin "getting wasted" in Miami. Lo shakes her head, reminding Steph how they tried to confront Kristin about her bad behavior before things got out of hand. Stephanie worries that Kristin's (alleged) recreational drug habit could turn into a full-fledged addiction. On a different subject, Steph tells Lo she's looking forward to seeing Spencer and Heidi at Kristin's -- especially since she hasn't heard from either of them in months. "Why does Spencer ignore you?" Lo wants to know. "He's your big brother!"Across town in Pacific Palisades, Heidi and Spencer are grabbing a bite at Cafe Vida -- and wondering how Heidi's new "assets" will go over with their friends. Heidi admits she can't wait to show off her "new body" while Spencer says he's concerned about running into Stephanie. Heidi tells Spencer she'd love to see him make up with his sister, but he insists that her DUI was "the final straw" and says he plans to avoid Stephanie "like the plague."After leaving Audrina's, Kristin heads over to Dime Bar to visit Stacie -- and tell her why she thinks Stephanie started those rumors after all. Stacie agrees Lo probably wasn't involved (according to her, Lo is "too much of a chicken") but tells Kristin she's not sure why Steph would want to tear her down. Kristin stands by her suspicions, claiming Stephanie is "crazy," bored with her life and a "pathological liar," and tells Stacie she plans to confront her at the party. ("You need to kick her ass," Stacie advises.)So what do the boys think of all the drama? Frankie and Brody meet up to shoot some hoops -- and catch up on all the latest gossip. Talk quickly turns to Audrina's new boyfriend, Ryan (Brody admits he and Ryan have "had some issues" in the past), and Brody admits he'll be scoping out Audrina at the party -- whether or not she's flying solo. The boys joke that Audrina and Ryan have a lot in common (they've got same taste in clothes and hair straighteners!) then move onto another topic: the Kristin rumors. Brody immediately jumps to Kristin's defense, claiming Stephanie is the one who made up those lies, and hinting that Steph oughta keep her mouth shut, in light of her own history. Meanwhile, Frankie seems more interested in another subject: Heidi's cosmetically enhanced breasts. Both boys wonder what Heidi will look like now that she's "transformed [herself] into Lady Gaga."Party time! Audrina and Ryan joke around with Stacie, but things get a little uncomfortable when Brody and Frankie arrive. Soon after, Speidi arrives on the scene and Heidi creates a minor stir by showing off her brand-new breasts and admitting that she wanted them even bigger. ("H's for Heidi!") Across the room, Spencer surprises Kristin with a giant crystal ("they've calmed me down a lot," he says) then Kristin finds Heidi and tells her someone's been spreading rumors about her.Just then Stephanie arrives and tells Lo she's having second thoughts about confronting her brother. Before Lo can respond, Kristin steps in to accuse Stephanie of "saying a bunch of stuff" that isn't true. Stephanie denies starting any rumors -- and suggests that Kristin ask the people she's been "partying with." Enraged, Kristin tells Stephanie she doesn't believe her, before storming off.Later that night, Brody kicks the party into high gear by checking out Audrina -- and warning Kristin that Stephanie's up to no good. Kristin tells Brody her suspicions about Spencer's sis, and Brody eggs her on, telling her he's "positive" Stephanie was the one behind all the smack talk.Meanwhile, Stephanie (who's still shaken up from her confrontation with Kristin), tells Lo she wants to go home, yet Lo encourages her to talk to Spencer first. Stephanie goes over to chat up Heidi and Spencer and quickly bursts into tears after her brother gives her the cold shoulder. Seeing Stephanie upset, Spencer calls her a "crazy bitch" declaring he doesn't have room in his life for "crying sisters." While Brody laughs from the sidelines, Audrina rushes over to comfort Stephanie, telling Stephanie her brother's "off his rocker."The next day, Lo and Stephanie meet up at the M Cafe to discuss all the drama that went down at Kristin's. After deciding that Spencer's officially "lost his mind," Stephanie tells Lo that Kristin sent her a text saying she wants to talk. Lo admits she's not sure why Kristin's upset, insisting that "none of us did anything wrong," but encourages Steph to meet with her, saying it's better to clear the air and "put it to rest."Across town, Charlie tries to find out what Stephanie did to set Spencer off at the party. When Spencer refuses to accept any responsibility for Steph's "waterworks," Charlie hints that Spencer needs to make room in his life for people other than Heidi. When Spencer insists that the crystals are helping him keep it together, Charlie points out they aren't working. "You're crazy," he says, shaking his head. "You lost it."As the episode wraps up, Kristin sits at the Melgard Public House waiting for Stephanie to arrive. When Stephanie joins her, they skip the small talk -- and move right into another heated discussion about the rumors. Taking Lo's advice, Stephanie tells Kristin she's ready to put what happened in Miami behind her. Kristin lashes out, snapping that it won't be over until Stephanie stops "telling people stuff" about her. The girls argue about who's responsible for the stories in the tabloid and Stephanie accuses Kristin of blaming everyone else for her own actions.Things become heated when Kristin accuses Stephanie of bringing drama everywhere she goes -- citing her "screaming match" with Spencer as proof -- and Stephanie calls Kristin a "mean person" with a "bitchy attitude." When it becomes clear that neither girl is willing to apologize, Stephanie storms off -- but not before calling Kristin "delusional."