You have to sign the equivalent of the Official Secrets Act to get into the BBC studios in Cardiff where they film Doctor Who. You will not photograph, record or discuss anything you see. You can go to the Doctor Who Experience down the road if you want to see models of Daleks, but the studio is top-security. This makes it hard to do an interview with Peter Capaldi, and I can’t understand why we’re not meeting in Crouch End, near our respective homes. But Doctor Who, I soon learn, is a cult and I am penetrating its Holy of Holies. Trouble is, it’s a cult I don’t belong to, so when the press officer says, in awed terms, that she might be able to