The play, inspired by the acclaimed Granada Television series "Seven Up!," follows three participants – working-class Alan (Kennedy), upper-class Catherine (Harker) and middle-class Tom (Weir) – who, as part of a social litmus test, are reunited every seven years to have their lives scrutinized by the nation and each other, as part of a television documentary series. But waiting on the sofa for director David to arrive, they reveal far more to each other than they ever will to the camera.

Playwright Alexis Zegerman won Soho Theatre's Westminster Prize for New Writing in 2003 and writes extensively for BBC Radio. As an actor, she can currently be seen as Zoe in Mike Leigh's latest film "Happy Go Lucky." This is her first full-length play. In a press statement, she says of the work, "It's about growing up, class, hope, love and disappointment, but most importantly it's about the effect that these people have on each other through this strange thing that joins them together."

Harker is well known for her BAFTA-nominated performance in "House of Cards" and as Jane Bennett in the acclaimed BBC adaptation of "Pride and Prejudice." Her extensive theatre credits include On the Shore of the Wide World (at Manchester's Royal Exchange Theatre and subsequently the National's Cottesloe), Three Sisters (at the West End's Playhouse Theatre), Uncle Vanya (at the Dublin's Gate Theatre and subsequently at New York's Lincoln Center Festival), Tartuffe (Almeida) and The Debutante Ball for Hampstead Theatre.

Kennedy was nominated for the MEN Best Actor Award for his performance in the Hampstead Theatre/ETT production of Jonathan Harvey's Hushabye Mountain. Other theatre credits include Edmund (with Kenneth Branagh at the National), Death of a Salesman (also National) and Dealer's Choice (Vaudeville Theatre).

Weir recently performed in the RSC Complete Works Season alongside Tamzin Greig in Much Ado about Nothing and King John. Other credits include Pera Palas at the Gate, and Amy's View and Arcadia at Manchester's Library Theatre (nominated for Best Actor in the Manchester Evening News Theatre Award for the latter). The play is directed by Hampstead's artistic director, Anthony Clark.

Michael Apted's "Up!" series began as a World in Action documentary in 1964, with a group of seven-year-olds from socially diverse backgrounds interviewed on camera. The idea was to explore the notion that class structure in the U.K. was so strong that it could pre-determine a person's life path. Since the first film, the same individuals have been persuaded to participate every seven years (although some have dropped out and some have missed years). The next film is expected to be made in 2011. The characters in Lucky Seven, however, are entirely fictional and in no way connected to the TV series.

To book tickets contact the box office at 020 7722 9301 or visit www.hampsteadtheatre.com.