"We are aware that Peter Capaldi’s played a big part in Doctor Who before and we’re not going to ignore the fact, and Torchwood," Moffat said. "I’ll let you in on this. I remember Russell [T. Davies] told me he had a big old plan as to why there were two Peter Capaldis in the Who universe, one in Pompeii and one in Torchwood. When I cast Peter and [Russell] got in touch to say how pleased he was I said, 'Okay, what was your theory and does it still work?' He said 'Yes it does, here it is.' So I don’t know if we’ll get to it. We’ll play that one out over time. It’s actually quite neat."
The Doctor Who Fiftieth Anniversary Special is set to air on November 23, followed shortly thereafter by the Christmas Special, which will be Capaldi's first appearance as The Doctor.