Anne Louise Dudek (born March 22, 1975; Boston, Massachusetts) is an American actress, known for her role as Dr. Amber Volakis on the television show House and her leading role on UK television series The Book Group as well as playing Francine Hanson in the series Mad Men. In 2010, she joined the cast of Covert Affairs.

From the mid-1990s (while at Northwestern University) through 2001, Dudek appeared in various theater productions and on Broadway. She made her Broadway debut in Wrong Mountain in 2000, and won the Connecticut Critics Circle Award for outstanding performance in The Glass Menagerie.

After success on Broadway, she made the jump to television, with her first starring role coming on the British comedy drama The Book Group. She has since guest starred on other TV shows, including Desperate Housewives (as Karl Mayer's girlfriend in Season 1), How I Met Your Mother (as Ted's Krav Maga-trained ex-girlfriend), Friends (as 'Precious', Mike Hannigan's girlfriend), Charmed, Bones (as Seeley Booth's lawyer girlfriend), Numb3rs and Six Feet Under. She also played Lucinda Barry in the pilot episode of Psych, and a teacher who has a sexual relationship with one of her students (based on the case of Debra Lafave) on Law & Order: Criminal Intent.

Sendhil Ramamurthy (Kannada: ಸೆಂಥಿಲ್ ರಾಮಮೂರ್ತಿ, Tamil: செந்தில் ராமமூர்த்தி; born May 17, 1974) is an American actor. He played geneticist Mohinder Suresh in the NBC Sci-Fi drama Heroes and, as of 2010, he plays Jai Wilcox in the Action Spy series Covert Affairs. He appeared in the film Shor in the City.

Ramamurthy was born in Chicago to Hindu Indian immigrant parents. His father is a Kannadiga and his mother is a Tamil and both are physicians. He has one sister who is also a physician. He and his sister were raised in San Antonio. There, he went to Keystone School and graduated in 1991. He is the cousin of film director Jay Chandrasekhar. Ramamurthy is married to actress Olga Sosnovska and the couple have two children. Their daughter, Halina, is four years old, and son, Alex, is two years old.

Ramamurthy attended Tufts University initially as a pre-med major to follow in his parents' footsteps. He was also a member of the Kappa Charge of Theta Delta Chi. He became interested in acting when he took an "Intro to Acting" class during his junior year as part of his graduation requirement. After participating in several plays — including Our Country's Good, he chose to change career goals. He graduated with a bachelor's degree in history and then attended the Webber Douglas Academy of Dramatic Art in London, from which he graduated in 1999.

Robert Sean Leonard (born Robert Lawrence Leonard, February 28, 1969) is an American actor, who has regularly starred in Broadway and off-Broadway productions. Since 2004, he has played the role of Dr. James Wilson on the television series House, M.D.. He played Neil Perry in the 1989 movie Dead Poets Society.

Leonard was born in Westwood, New Jersey, the son of Joyce P. (née Peterson), a nurse, and Robert Howard Leonard, a Spanish teacher. He grew up in Ridgewood, where he attended Ridgewood High School before moving on to Fordham University and later Columbia University School of General Studies (GS). Because he shares his birth name with another actor, he uses the name of his brother Sean for his Screen Actors Guild membership.

Leonard is a three-time Tony Award nominee (1993, 2001 and 2003), winning in 2001 (Best Actor – Featured Play) for his role as A. E. Housman in Tom Stoppard's The Invention of Love. He had a prior association with Stoppard's work, creating the role of Valentine in the New York premiere of Arcadia at Lincoln Center in 1995. His 2003 Tony nomination was for his portrayal of Edmund Tyrone in a well-received revival of Eugene O'Neill's Long Day's Journey Into Night that co-starred Philip Seymour Hoffman and Brian Dennehy. Leonard has also appeared in Broadway musical productions, in 2001 replacing Craig Bierko as the lead performer in a successful revival of The Music Man. On February 8, 2011, it was announced that Leonard will co-star as Paul Verrall in the 2011 Broadway revival of Born Yesterday beginning in March.