James Fox is an actor of great international repute and we were extremely fortunate to secure his services as Professor Chronotis. Watch his performances in films like The Servant, A Passage to India or The Remains of the Day, in which he plays Anthony Hopkins's morally ambiguous master Lord Darlington, and you'll see why he is so much in demand.

I think it was James's performance as the fuddy-duddy Professor Summerlee in The Lost World, a lavish BBC adaptation made a couple of years ago, which actively brought him to my mind as Chronotis. I scarcely dared hope that he might say yes, and of course I was delighted when his agent rang to say that James loved the script and would like to play the Professor.

It turned out he was an old family friend of Lalla Ward's - I'd had no idea of this when I cast him, but showbusiness is a surprisingly small world and it's remarkable how often these things happen. And what a perfect gentleman and a delightful colleague he was.