Inevitably you work with different actors in different ways, because each actor is a unique personality. How would you sum them all up? They're all so different.

Colin Baker is a very, very professional and very caring actor who thinks very hard about his part, and of course is actually quite a Doctor Who fan. He really knows his Doctor Who mythology inside out and it's great working with Colin. Peter, again a consummate professional, a very quick actor. He goes straight in and he's quite often a one take wonder.

Sylvester, how do you sum up Sylvester? He's fabulous, he's bonkers and it's glorious. [He has] a very strong individual characterisation of the Doctor, and it was fabulous fun working with him on Bang Bang A Boom just recently, absolutely wonderful.

And now Paul, who is a terrific actor in every respect. He's very easy going, very easy to work with, listens very carefully in the studio when we're talking through a scene and deciding what to do with it. He's full of ideas and he'll come up with all sorts of brilliant contributions and is a marvelous actor to work with. I just feel so lucky to be working with people like this.