Eddie Murphy plays seven roles in this Jekyll-&-Hyde comedy. Murphy stars as Dr. Sherman Klump, a kind, calorically challenged genetics professor who longs to shed his 400-pound frame in order to win the heart of beautiful Jada Pinkett. So, with one swig of his experimental fat-reducing serum, Sherman becomes " Buddy Love", a fast-talking, pumped-up, plumped-down Don Juan. ...

Having seriously dated for one week, Marissa & Ryan are progressing slowly. Summer (recurring guest star RACHEL BILSON) tries to deny her true feelings for Seth as she witnesses Anna (recurring guest star SAMAIRE ARMSTRONG) & Seth getting closer. Meanwhile, the case against Kirsten's father, Caleb (recurring guest star ALAN DALE), continues to cause friction between Sandy & Kirsten. & Julie (recurring guest star MELINDA CLARKE) tries to mend her relationship with Marissa, inviting her, Jimmy & Ryan to attend her charity event--where her new relationship is revealed. ...

When Seth tries to choose between dating Summer (recurring guest star RACHEL BILSON) or Anna (recurring guest star SAMAIRE ARMSTRONG), he ends up in the middle of a very complicated situation. Meanwhile, Ryan visits his brother, Trey (recurring guest star BRADLEY STRYKER), in prison, accompanied by Marissa. When Julie (recurring guest star MELINDA CLARKE) finds out that Marissa is with Ryan in Chino, she becomes furious. As everyone nervously waits at the Cohen house for Ryan & Marissa to return, tensions mount, making the holiday a Thanksgiving to remember. ...

After Thanksgiving, Anna (recurring guest star SAMAIRE ARMSTRONG) & Summer (recurring guest star RACHEL BILSON) remain upset with Seth for his behavior on the holiday, & Seth struggles to reconcile with them. Meanwhile, Julie (recurring guest star MELINDA CLARKE) has relationship problems of her own. Jimmy & Sandy team up to tackle Jimmy's legal issues. A secret indiscretion by Kirsten is exposed. Ryan & Luke become partners on a history project, & an astonishing revelation creates an unexpected alliance between them. ...

Kirsten's rebellious 25-year-old sister, Hailey Nichol (recurring guest star AMANDA RIGHETTI), comes to town on New Year's Eve, causing turmoil in the Cohen household. Ryan & Marissa plan a quiet evening of popcorn & movies at home, but Marissa later decides to attend a party hosted by a young man, Oliver Trask (recurring guest star TAYLOR HANDLEY), who goes to the same therapist as she does. Meanwhile, Hailey persuades Sandy & Kirsten to go out so she can have a raging party in their house for a few friends. As the clock ticks closer to midnight, Ryan hopes that he can make it to Marissa in time for their first New Year's kiss together. As of this episode, MELINDA CLARKE as Julie Cooper & RACHEL BILSON as Summer Roberts are series stars. ...

Kirsten's unemployed sister, Hailey (recurring guest star AMANDA RIGHETTI), moves in with the Cohens & disrupts the entire family when she behaves as the houseguest from hell. Hailey depletes the refrigerator, controls the television, disrespects Kirsten & shows no signs of leaving anytime soon. Desiring some time alone with his wife, Sandy urges Kirsten to resolve the problem with her sister. When Kirsten can't confront Hailey, Sandy angrily tells Hailey that everyone is tired of tolerating her rude behavior. Meanwhile, Seth & Anna (recurring guest star SAMAIRE ARMSTRONG) struggle with telling Summer the truth that they are now a couple. Ryan feels jealous about Marissa's new friend, Oliver (recurring guest star TAYLOR HANDLEY), a neglected, drug-abusing teen she met in therapy who always seems to show up when Ryan wants some privacy with Marissa. Later, Ryan helps Oliver by asking Sandy to intervene when Oliver is arrested for trying to buy drugs from an undercover cop. ...

Ryan, Seth, Marissa, Anna (recurring guest star SAMAIRE ARMSTRONG), Luke & Summer head to Palm Springs for a parent-free weekend at the home of Marissa's new, troubled friend Oliver (recurring guest star TAYLOR HANDLEY). Hoping to spend some time alone with Marissa, Ryan, who is neither interested in golf nor spas, reluctantly agrees to make the road trip with Luke. Oliver quickly irritates Ryan by flirting with Marissa & deliberately keeping the couple apart. & Summer uses every method she can to annoy Seth & Anna. The weekend goes from bad to worse when Oliver angrily leaves the house only to later phone Marissa with news that he's taken a handful of drugs to commit suicide. Marissa & Ryan race to a hotel where Oliver seems to be shaken but in no apparent danger of overdosing. Ryan is unconvinced that Oliver even attempted to take his life, & much to Ryan's dismay, Marissa insists on staying the night alone with Oliver. ...

Sandy & Jimmy begin a new business partnership when they buy The Lighthouse, a beloved Newport restaurant. Meanwhile, Kirsten & Julie become workmates when Julie is hired as Newport Group's new model-home designer. Also, Seth's jealousy of Summer's new boyfriend causes Seth to doubt his relationship with Anna (recurring guest star SAMAIRE ARMSTRONG). & Ryan loses control while trying to prove that Marissa's troubled friend Oliver (recurring guest star TAYLOR HANDLEY) is a fraud, leaving Seth & the Cohens concerned & afraid for Ryan. ...

Caleb (recurring guest star ALAN DALE) once again puts Kirsten in a difficult situation when he forces her to terminate Julie. After yet another crisis with Ryan, Sandy & Kirsten question their decision to bring him into their home. Meanwhile, Ryan & Luke become allies in their quest to protect Marissa from Oliver (recurring guest star TAYLOR HANDLEY). When Marissa discovers the truth about Oliver, a tense showdown ensues--and Sandy & Ryan must come to the rescue. ...