Heidi and Spencer head down the aisle and two unexpected guests manage to attend the ceremony.

Lauren and Whitney go to Paris, but the trip is marred for Lauren when she finds out Brody is seeing someone new. Meanwhile, Spencer follows Heidi to Colorado to try to win her back.

Brody is still in jail, so the girls try to come up with a way to get him out. Plus Audrina and Lauren finally sit down and talk to each other.

Lauren and Audrina find out that Spencer has a sister. She also pays Spencer and Heidi a visit. When Lauren and Audrina hang out with Brody, they not only run into Spencer's sister, but also run into Justin - with another girl.

Broken hearts as far as the eyes reaches: Heidi and Spencer can't agree on their wedding plans while Brody and Lauren both refuse to make the first step.

Spenser is asked by Heidi to make amends with Lauren in hopes that she'll attend their wedding. Elsewhere, a recently fired Stephanie has a run-in with Kelly Cutrone, her former boss.

The third season premieres with Lauren and Heidi still unable to get past their differences and having become mortal enemies. Meanwhile, Whitney has graduated from college and is now juggling a real job and Audrina has become Lauren's new roommate and best friend.

Stephanie tells Spencer that Heidi might bail out of the wedding, so Spencer and Heidi fight once again. Lauren and Audrina both have a date.

The tension between Lo, Lauren and Audrina continues and soon things reach boiling point.

Lauren ("LC") moves from Laguna Beach to Los Angeles where she plans to apply for an internship at Teen Vogue and attend fashion school. Alongside her is best friend Heidi who is pretty much just into the party scene. The real test of Lauren's new life is if she can juggle work, school, and partying. However, no matter where she goes, drama always seems to follow.

After their week in Paris, Lauren and Whitney are back home and have to adjust to the changes and the changes they plan to do.

The gang make their return to Los Angeles. Meanwhile, Brody and Audrina deal the repercussions from their hookup in Hawaii.

As if Lauren's falling off with Heidi wasn't enough, another one of her eldest friends, Jen, has eyes for Brody. Jen feels guilty for hooking up with Brody but Heidi encourages her to go for what she wants. Clearly, there is a lot more to mend in their relationships and Lauren assures Heidi that they'll never be the same as long as Spencer's still in her life.

Lauren lands in tears during her surprise birthday party when Heidi rocks the boat by showing up uninvited. Plus, Spencer takes a swing at Stephanie's ex-boyfriend, Cameron.

Heidi throws a party for her birthday where Audrina shows up to try and make amends. However, Heidi refuses to listen.

Spencer refuses to let go of Heidi. Meanwhile Lauren and Whitney are on the spot, because "super-intern" arrives at Teen Vogue.

Lauren tries to uphold her friendship to Audrina, but is it already too late? Meanwhile Spencer tries to win Heidi back and risks her career to do so.

Heidi finds out the results of her pregnancy test while Lauren and Whitney are asked to cover a major fashion show. Meanwhile, Audrina turns Spencer down when he asks her out on a date.

Lauren tries to make peace with Heidi, but is instead stood up when Heidi decides to meet up with Spencer instead. Meanwhile, Whitney finds herself annoyed at the fact that she is not respected as a Teen Vogue intern.

Heidi decides to throw Lauren a surprise 21st birthday party and tells her about Spencer asking her to move in with him. Jen tries to apologize to Lauren but instead makes excuses, thus, Lauren doesn't accept her apology.

Whitney is getting ready to work with Teen Vogue after graduation, however, she has a lot of competition with other interns. She also gets to model at "Good Morning America." Meanwhile, Spencer still insists that Heidi move in with him.

When Jen wants to be friends again with Lauren, however the dark past starts to haunt everyone. And not everyone likes the past revealed.

A blowout trip to Las Vegas turns sour when Audrina snubs Lauren, Brody brings up Stephanie's past and the boys end up in jail.

The season four finale finds Lauren and Heidi running into each other and are reminded why the once were best friends. Meanwhile, as Heidi's mom pays a visit, the she and Spencer know they must face reality; and Audrina is surprised by Justin with a trip to Palm Springs.

Lauren is not at all thrilled in Heidi's decision to get back together with Spencer. The situation between best friends becomes even more heated and leaves their relationship hanging.