Alex Kingston, who played the Doctor’s wife, River Song, regularly between 2008 and 2015, says she doesn’t think Billie Piper really is the next Doctor.

We saw Ncuti Gatwa’s Fifteenth Doctor regenerate into Billie Piper at the end of The Reality War, though there’s a suggestion that this was a last-minute change to the finale. Alex isn’t convinced:

“I didn’t see the Billie Piper twist coming at all. To be perfectly honest, I still don’t quite believe it because she’s not a Gallifreyan; she’s a human. I think there’s some playing going on here. But I don’t buy that she’s the next Doctor, and if she is, they’re gonna have to work hard to convince me, because she’s not a Gallifreyan!”

I think Kingston has it in her head that this is some variation of Rose Tyler, the Ninth and Tenth Doctor companion that Piper previously played. And as such, she’s right: Rose isn’t a Time Lord.

But the question remains: is she the Sixteenth Doctor?

The ending didn’t credit Billie as the Doctor, as you’d normally expect, so Alex might be right in thinking there’s something going on. The Doctor might be reusing a face again, as the character has done with the Fourteenth Doctor (played by David Tennant, who was, of course, the Tenth Doctor), but would Russell T Davies, showrunner on Doctor Who, pull the same trick again? It’s certainly possible, but we hope it’ll be a bit more interesting than that.

We’ve a while to wait in order to find out: Doctor Who returns this Christmas with a festive special…