Amid the lies and deceit that make nothing what it seems in The Prestige, the only character you can trust is Sarah, the faithful wife of Christian Bale's tormented magician. In Starter for Ten, college student James McAvoy is so smitten with a snobby rich girl he fails to notice that the campus political activist Rebecca Epstein truly loves him.

What's interesting about debutant Rebecca Hall, who plays both roles, is that since graduating from Cambridge three years ago she has rapidly built a reputation with her stage performances in As You Like It, Shaw'sMan And Superman, Moliere's Don Juan and Timberlake Wertnebaker's Galileo's Daughter, all of which were directed by her father, Sir Peter Hall.

Her mother is the American opera star Maria Ewing, who was her father's third wife, is similarly industrious. Hall, who has six children from his four marriages . . . when he was married to Leslie Caron I once mistook him for a waiter at White's Hotel during the Wexford Opera Festival . . . is now married to screenwriter Nicky Frei.

"I think people are constantly surprised by how homely we all are, despite being so dispersed, " says Rebecca.

"I don't think dad has much of a social life outside the rehearsal room, but he does have his family."