There was, however, one teeny-tiny little potential fly in the ointment: The actor had already appeared on the series in a significant guest role — as Caecilius in “The Fires of Pompeii.” And, not only that, he had also shown up in all five episodes of the TORCHWOOD story “Children of Earth,” as John Frobisher.
This is not unprecedented, even for a Doctor; Colin Baker previously played Commander Maxil before donning the hideous garb of the Sixth Doctor. But back then, fans didn’t have instant access to clips of the actor’s previous appearance, nor did they have the Internet (as it currently exists) to discuss/agitate/troll about it. Nowadays, “recycling” an actor gets noticed.
After Freema Agyeman was cast as companion Martha Jones, then-showrunner Russell T Davies had to explain away the actress’ small role in “Army of Ghosts,” Adeola Oshodi, as Martha’s cousin. (Because we all know that on TV identical cousins are the norm.)
Interestingly, current executive producer Steven Moffat did not feel the need to connect Amy Pond with actress Karen Gillan’s previous role as the Soothsayer in “The Fires of Pompeii”; but perhaps he will address it, however, because the showrunner has said that he will be explaining why the 12th Doctor looks exactly like Caecilius.
In an interview with Nerd3, Moffat said:
“We are aware that Peter Capaldi’s played a big old part in DOCTOR WHO and TORCHWOOD before, and we are not going to ignore the fact.
“I remember Russell told me that 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?” and he said, ‘Yes, it does. Here it is…’ We’ll play that one out over time. It’s actually quite neat.
“The face is not set from birth. It’s not like he was always going to be one day Peter Capaldi. We know that’s the case because in ‘The War Games’ [the Doctor] has a choice of faces. So we know it’s not set — so where does he get those faces from? They can’t just be randomly generated because they’ve got lines. They’ve aged. When he turns into Peter he’ll actually have lines on his face. So where did that face come from?”
This is a very interesting concept, and it could make for an intriguing storyline. I’m hoping it isn’t something along the lines of “The Doctor subconsciously took note of an interesting face and unconsciously chose it during regeneration.” Perhaps the case is that there are certain “important” people in the universe — e.g. Caecilius, Frobisher and now the Doctor — and they keep being born with the same face until they fulfill their destiny, or whatever.
I don’t know; I’m just reaching here. Let’s wait and see what Davis came up with, and how much of it Moffat uses.