It's opening night at The Belgrade. The curtain will rise on a play performed by a very special cast. Troubled, traumatised or suffering a tragedy, the stars of this show are a very special group of teenagers. At stake if their performance gets a bad review, the very future of a world-renowned and much-copied arts project pioneered 50 years ago in Coventry itself. Will the Class of 2015 save the day? Or will the age of austerity deny the theatre a happy ending? Alistair McGowan tells a story of our times.