"If I tell you anything at all I'll have to kill you and then kill myself. I wasn't even allowed to tell my children I was actually in it for about four or five weeks! Once we filmed in Trafalgar Square I knew it would be impossible to keep that under wraps! But what do you do? I was going to work and not being able to tell anyone what I was doing! It was like joining MI6!
"What I can tell you is that it's absolutely bloody brilliant! I think it's an astonishing script. Stephen Moffat is an outrageously good writer and as always with Doctor Who, it's philosophical, it's deep, it's an adventure story and if you're a kid, you're going to be taken on an extraordinary ride. It raises all sorts of interesting questions for anyone who wants to go deeper with it. It's funny and then on a sixpence it breaks your heart. It's just wonderful!"The 50th anniversary special airs on November 23.
[Source: What's On TV]