starred in the television series The Pitts, playing Faith Pitt. She gained wider notice for playing Janis Ian in the 2004 film Mean Girls. She played Avery Bishop in the second season of Tru Calling. In 2005, Caplan played troubled sister Marjee Sorelli in Related, a one-hour comedy-drama on The WB that was canceled after one season. In 2006, she starred as Sara Weller in the thriller film Love is the Drug and was named one of "10 Actors to Watch" by Variety. After Related ended, Caplan was cast in the CBS sitcom The Class, which premiered in September 2006 and lasted for one season. She played Kat Warbler, one of several elementary school friends that reunite after 20 years. In 2008, Caplan played Marlena Diamond in the film Cloverfield and was nominated for a Saturn Award for Best Supporting Actress. She also appeared as Ami in the romantic comedy My Best Friend's Girl. Later that year, she guest-starred as Amy Burley on the HBO vampire show True Blood. She was the voice of Faith Pitt in the proposed animated version of The Pitts, which was developed in 2007. She also appeared in the critically acclaimed Starz ensemble comedy Party Down, playing a struggling comedian who is part of a catering crew. In 2010, she appeared in 127 Hours. In early 2012, Caplan premiered two films at the Sundance Film Festival: Save the Date and Bachelorette. Also in 2012, she appeared as Julia in several episodes of the Fox sitcom New Girl. She played Agent Lacey in the 2014 film The Interview. Masters of Sex (2013–2016) In 2013, she began playing 1960s human sexuality pioneer Virginia E. Johnson on the Showtime series Masters of Sex. Caplan also provided her own vocals for a cover version of the song "You Don't Know Me" in the Masters of Sex episode "Phallic Victories". Her performance on the show was well-reviewed, and on July 10, 2014, she was nominated for the Primetime Emmy Award for Outstanding Lead Actress in a Drama Series. Caplan was cast in her role as Johnson before they signed her co-star Michael Sheen as William H. Masters because he was busy working on another production. Producer Sarah Timberman said of Caplan, "The minute we met Lizzie we thought that she just embodied so much of the spirit of Virginia Johnson." Caplan also stated herself that as a single woman pursuing