Billie Piper Isn’t The Sixteenth Doctor – But She Is a Classic Time Lord, According to Convincing Theory

Even though it seems that Billie Piper will be portraying the next incarnation of the Doctor in Doctor Who, according to this convincing theory, there’s a good chance she’s actually playing a different legendary Time Lord. Following the shocking regeneration of the Fifteenth Doctor in the Season 15 finale, “The Reality War,” audiences were shocked to see Doctor Who alum Billie Piper appear on their screens in the final moments of the episode. Piper is set to star in the upcoming Doctor Who Christmas special in 2026, but showrunner Russell T Davies has yet to actually confirm whether she is taking on the role of the iconic titular character or not.

While the future of Doctor Who is somewhat secure for the time being, viewers are curious about what next year’s installment will look like. It seems obvious that Billie Piper is the Sixteenth Doctor, but the Whoniverse is never quite that simple, something that dedicated audiences are very much aware of. While Piper could be the Doctor, Rose Tyler, or even the Moment again, it’s worth taking a look at this intriguing Doctor Who theory and considering whether she is instead portraying another familiar figure.

Billie Piper Has Not Been Confirmed as the Sixteenth Doctor in ‘Doctor Who’ Yet

The most important thing to note about Doctor Who right now is that the show has not confirmed exactly who Billie Piper is playing. Of course, Doctor Who audiences know that Piper played companion Rose Tyler and the Moment, the interface of the device used to end the Time War, in the 50th anniversary special “The Day of the Doctor.” While she is standing in the place of Ncuti Gatwa’s Fifteenth Doctor after regenerating at the end of “The Reality War,” this doesn’t necessarily mean she is the Sixteenth Doctor. Doctor Who audiences know that nothing is ever straightforward.

The fact that this scene is so brief, and we only really see Piper’s face, suggests there is more than meets the eye. Of course, this was likely done in order to keep this huge twist under wraps, but at the same time, Doctor Who goes to extreme lengths to avoid sharing any story details until absolutely necessary, too, which perhaps means that whatever happens next isn’t as simple as implied.

In the past, Doctor Who‘s credits have included a note introducing the actor portraying the new incarnation of the Doctor after a regeneration, but Piper didn’t receive this treatment, interestingly. Until Doctor Who showrunner Russell T Davies directly confirms this, the possibility that Piper is playing someone else cannot be ruled out. This is where this Doctor Who theory comes into play. The Fifteenth Doctor has regenerated; we know that for certain, but maybe Piper isn’t the Time Lord we’re expecting.

Billie Piper is Playing Susan Foreman in ‘Doctor Who’ Theory, Explained

BBC/Disney

To fully understand this theory, it’s worth revisiting the Doctor Who Season 14 finale. The return of the Pantheon God Sutekh, who hadn’t appeared in the show since the Fourth Doctor’s era, is an astounding moment in Doctor Who​​​​​​. The revelation that he had been attached to the TARDIS for centuries of the Doctor’s life is even more shocking, but because the villain is defeated so quickly, it’s easy not to think too much about how he did this.

In “Pyramids of Mars,” the Fourth Doctor banished Sutekh by using a time corridor, and the god claimed that he latched onto the TARDIS after this. However, we know that Sutekh was able to see across time and set traps, hence the existence of Susan Triad. Plus, we have to take Sutekh at his word that he grabbed onto the TARDIS straight away, but there’s a chance he didn’t leave the time corridor immediately and could be simply lying.

Doctor Who teased the possibility of Susan Triad being Susan Foreman, but this was ultimately disproven. However, Sutekh must have been aware of the Doctor’s granddaughter in order to set this trap, as it seems like far too much of a coincidence otherwise. This theory suggests that Sutekh snatched Susan Foreman from the time corridor and trapped her within the TARDIS as the ultimate hostage.

It’s important to remember that while Doctor Who‘s extended media has released stories about both Susan and Sutekh, the show’s lore generally takes precedence. Therefore, anything established in Doctor Who‘s prose stories or the Big Finish audio dramas isn’t necessarily still canonical in the show.

There is evidence to support this claim. When the Fifteenth Doctor has a vision of Susan in “The Interstellar Song Contest,” she is in the current version of the TARDIS, not the one she traveled in as an active companion during Doctor Who‘s classic era. Although these two TARDIS designs share some resemblance, they are different. This implies that Susan is stuck in the Doctor’s “here and now,” as it were. Audiences also know the TARDIS has emergency protocols that can kick in when the Doctor is in danger, and seeing as the Time Lord is on the verge of death while freezing in space in this scene, it would make sense for this to happen.

But why would Susan appear now, and not earlier? It seems likely that the Doctor and Ruby defeating Sutekh in “Empire of Death” is allowing Susan to be heard better, but there’s a chance the glitches play a part in this, too. In Doctor Who‘s scrapped Season 15 finale, it would’ve been revealed that Poppy is Susan’s mother, finally giving audiences an answer about the very first companion’s origins. In this scene, Susan and Poppy would watch the Fifteenth Doctor, Ruby, and Belinda celebrate from afar, but not interact with them. Seeing as Poppy is a glitch, perhaps Susan is also one, too. Poppy’s last moments are in the TARDIS just before the glitches “end,” and maybe that’s for a good reason.

Therefore, when the Fifteenth Doctor essentially punches the time rotor with regeneration energy, it allows Susan to escape. This wouldn’t be the first instance of a Time Lord jumping into the body of another, as both the modern and classic eras established multiple times, and it’s believed that Susan takes this opportunity to do so. It’s unclear exactly why Piper would portray Susan, rather than a new actor or Carole Ann Ford herself, but that’s the magic of Doctor Who, and perhaps the explanation for her appearance is as simple as the fact that she came from the Time Vortex and so looks like the Bad Wolf.

Since the release of “The Reality War,” audiences have been debating just who Piper will be playing in the Doctor Who 2026 Christmas special. While some would like to see the return of Rose Tyler once again, others believe it’s the Moment from “The Day of the Doctor.” However, something many have failed to consider is that Piper isn’t Rose, she isn’t the Moment, she isn’t even the Doctor–she’s Susan Foreman.

Release Date

May 11, 2024

Network

BBC One

Directors

Alex Pillai, Peter Hoar, Ben Chessell, Julie Anne Robinson, Jamie Donoughue, Amanda Brotchie, Dylan Holmes Williams

Writers

Steven Moffat, Pete McTighe, Kate Herron, Inua Ellams, Juno Dawson

Franchise(s)

Doctor Who / Whoniverse