Steven Moffat has said that there is no way that the character of River Song, played by Alex Kingston, can possibly be killed of.

Speaking at the post-premiere Q&A session at the BFI, the Moff was asked whether The Husbands of River Song would be the last time viewers would see River.

“Look, I killed her off in her first adventure, I wrote her as a ghost in another adventure, I wrote her into some mini episodes in a DVD - which was definitely her last appearance. There is no way to kill her off, she was dead in the first place”

River of course “died” in her first appearance on the show, 2008’s Silence in the Library, starring David Tennant as the Doctor. Steven went on to comment on how River pays little attention to which Doctor she’s accompanying.

“I think she’s always River and I don’t think she pays that much attention to which face he’s wearing. When she finishes an adventure I don’t think she remembers which one it was, it doesn’t matter - he is the Doctor - and she treats him sort of the same way as essentially fantastic, wonderful, the man she loves and slightly junior to her.”

Alex Kingston agreed:

“I feel she’s absolutely her own person and she adapts, but who she is in essence - I think - ultimately stays the same… I think that the way she treats the Doctor in these episodes, when she doesn’t realise who he is, I think is sort of quite indicative of who she is. It’s just that we haven’t gotten to see her very often playing outside of being with the Doctor.”

And Alex, like Peter Capaldi before her, described the upcoming Christmas as a “rollicking” adventure:

“I actually enjoy doing comedy and I don’t get that much opportunity, so to have a chance to do such a rollicking - like an old Hollywood comedy, the relationship between the two of us, it was just fantastic to have that opportunity.”

The Husbands of River Song airs this Christmas Day at 5:15pm on BBC One and 9pm EST on BBC America.