'The older I get and the more I do, the more nervous I become,' confesses Sir Derek Jacobi. 'It seems such a silly way to earn a living. I keep thinking 'why put yourself through these terrors?''.
This nervous knight is one of our greatest actors. He has starred in both popular TV and legendary classical drama. His sparkling career ranges from two years at the Birmingham Rep in the 1960s to the popular Cadfael TV series and the current Hollywood blockbuster Gladiator.
This year he returns, after four years, to his first love, and his greatest fear, the stage. 'There are no safety nets in theatre,' Jacobi smiles. 'The buzz is huge but this makes it very frightening.
'If it goes wrong, everyone sees it. When you're working with a camera, you can do it again. But on stage you never know how the audience are going to react; it's a two-way traffic in the theatre.'
But Jacobi loves the stage above film and TV because the actor has the freedom to make all artistic decisions about his performance.
'All the choices are there on show. There is no editor and no-one has done weird and wonderful things with visuals or music. You just see all the actor.'
Here he gestures from his head to his toes. Jacobi uses his hands all the time when speaking, like the most delicate of classical conductors. 'The theatre is the only place where the actor can make it happen.'
Jacobi knows the stage actor must deliver something very special: 'It's very easy to get rusty,' he says. 'I do live in terror of losing the trick of it. I've been out of practice for four years and I feel that I have to get the trick back. Part of this is facing an audience.'
The trick he talks of is insight and instinct, not artificial craftiness. It is ten days now until the world premiere of the play which has brought Jacobi back to the British stage. God Only Knows, which opens in Malvern at the end of August, is set in an isolated Tuscan farmhouse where four British tourists are holidaying. Jacobi plays a very unexpected stranger who arrives at the farmhouse armed and on the run.
Beyond this brief outline all is a mystery. The creative team are fanatical about not yet letting the world know the controversy which rages at the heart of the play.
The production reunites Jacobi with Hugh Whitemore, the acclaimed writer responsible for the duo's hit show about Alan Turing, Breaking the Code.
For Whitemore, it is his new play's hidden controversy which makes it particularly exciting: 'One hopes the audience will go home arguing furiously in the car,' he laughs.
'I want the audience involved, not just sitting there. If a play doesn't stay with them once they've left the theatre, what's the point?'
Jacobi also admits to being curious as to how the audience will react to the play's subject matter: 'There is something in the argument of the play which could very well upset people,' he says enticingly. …