Knightley plays Karen Wright, and Moss plays Martha Dobie, who together run a girls’ boarding school in 1930s New England, where they become entangled in a story of deceit, shame and courage when a schoolgirl's whispers spread, triggering a chain of events with extraordinary consequences.

Directed by Ian Rickson, the cast also features Ellen Bustyn (as Mrs. Amelia Tilford) and Carol Kane (as Mrs. Lily Mortar), as well as Lisa Backwell (Evelyn Munn), Isabella Brazier-Jones (Helen Burton), Poppy Carter (Janet), Marama Corlett (Lois Fisher), Nancy Crane (Agatha), Amy Dawson (Rosalie Wells), Isabel Ellison (Catherine), Bryony Hannah (Mary Tilford), Tobias Menzies (Doctor Joseph Cardin), Nathan Nolan (Grocery Boy) and Eve Ponsonby (Peggy Rogers).

Originally premiered on Broadway in 1934, The Children's Hour was last produced in London at the National's Lyttelton Theatre in 1994, in a production that featured Emily Watson, Harriet Walter and Clare Higgins.

Knightley is best known for her film appearances in "Bend It Like Beckham," "Atonement" with James McAvoy, "The Duchess," "The Edge of Love" with Sienna Miller, "Domino," "The Jacket," "Pride And Prejudice" (for which she was Oscar-nominated), as the feisty Elizabeth Swann in the "Pirates of the Caribbean" movies, and in the recently released "Never Let Me Go."

Moss, who is making her West End stage debut, is best known for playing the role of Peggy Olson in the ongoing award-winning television series "Mad Men," for which she has received both Emmy Award and SAG Award nominations, as well as for the role of Zoe Bartlett in "The West Wing." She made her Broadway stage debut in David Mamet's Speed-the-Plow in 2008. Film credits include "Get Him to the Greek," "Did you Hear About the Morgans?" and "Girl, Interrupted," as well as the forthcoming "On the Road" and "Darling Companion." Rickson was last represented in London by his production of Jerusalem that transferred from the Royal Court to the West End's Apollo Theatre and is now Broadway-bound for an April opening at the Music Box. Previous productions for the Royal Court, where he was artistic director from 1998 to 2006, include The Seagull (subsequently transferring to Broadway, with Kristin Scott Thomas), Krapp's Last Tape (with the late Harold Pinter), Mouth to Mouth (also West End) and The Weir (also West End and Broadway). Other credits since leaving the Royal Court include directing Parlour Song (Almeida), The Hothouse (National Theatre) and screen adaptations of "Fallout" and "Krapp's Last Tape."

The Children’s Hour is produced by Sonia Friedman Productions & Scott Landis.

To book tickets, contact the box office on 0844 871 7622, or visit www.ambassadortickets.com/comedytheatre.