Up until fairly recently, we'd assume that most of you hadn't heard of Susan Twist. The British actor has been performing since 1980, counting UK classics like Coronation Street, Brookside, The Bill, and The Archers among her many credits.
She first appeared in Doctor Who in the second 60th anniversary special, "Wild Blue Yonder." There, she played Isaac Newton's housekeeper Mrs. Merridrew in a scene which saw the Doctor and Donna Noble inadvertently inspire the scientist to go with "mavity" rather than "gravity."
We didn't give the character much thought after that, but eyebrows were raised when Twist seemingly showed up as an audience member in the club Ruby Sunday's band is playing during the opening few minutes of Doctor Who's latest Christmas Special.
She's uncredited for that appearance in "The Church on Ruby Road," but loudly asks the band to play an obscure 16th Century Christmas carol called "Gaudette."
Fans are also convinced they've spotted her in the trailer for Russell T Davies' new season 1, with the prevailing theory being that Twist could be the new big bad whom the Toymaker referred to as "The One Who Waits." Could the Doctor's inadvertent change to history with "mavity" have created a deadly new foe in this unassuming elderly woman? Or, is the BBC just re-using a relatively unknown actress?
It's hard to say for sure, but speculation is now running rampant about what Davies might be up to.
There are even some pretty wild claims that she's the original Doctor's companion, Susan, who may or may not be the Time Lord's granddaughter. Has she waited all this time for him, only to have been driven mad? If so, that would be a major deep dive into Whovian lore by Davies.
Last month, the showrunner talked more about what he hopes to bring to this new era of Doctor Who:
"Jodie Whittaker was the first female Doctor, many years too late, some would say, but my goodness she arrived in style. Now Ncuti Gatwa is the first Black doctor. It’s always pushing forward, it’s always got something to say and has always tried to welcome people in. From my point of view, whatever I make on television, I try to embrace queerness and queer politics and that’s like breathing to me because that’s my world. That’s how I live."
Do you have any theories about who - or what - Twist could be playing?