During her time on Veronica Mars, Bell appeared as Mary Lane in the film Reefer Madness: The Movie Musical, a reprise of the role she had played in the New York theatrical production of the musical upon which the film was based. She also portrayed the lead role in the 2006 film Pulse, the remake of a J-Horror film. In 2007, Bell joined the cast of the sci-fi television series Heroes, playing the character Elle Bishop, and the drama series Gossip Girl, as the off-screen titular narrator. In 2008, she played Sarah Marshall in the comedy film Forgetting Sarah Marshall, which garnered her fame. She has since appeared in a number of comedy films, such as Fanboys, Couples Retreat, You Again, and When in Rome. Bell also voices Lucy Stillman in the Assassin's Creed video game series and Princess Anna in the 2013 Disney animated film Frozen, the highest-grossing animated film of all time.