Who Is Doctor Who's Mrs. Flood? Here Are Our Best Theories

We've only had one full episode of Ncuti Gatwa as The Doctor, and there's already a big mystery surrounding his inaugural run. Surprisingly, the mystery has little to do with him, or even his new companion Ruby Sunday. Instead, Doctor Who fans are zeroed in on actress Anita Dobson, who stole the show with her final scene as Mrs. Flood in the 2023 Christmas special.

In the last moments of "The Church on Ruby Road," Mrs. Flood broke the fourth wall by asking the audience at home if they'd ever seen a TARDIS before. The fact that she was able to do that was shocking enough, but how exactly does this seemingly oblivious neighbor know what a TARDIS is? Furthermore, if she knows about the TARDIS, then she surely knows about The Doctor. It seems clear to me that there's more to Mrs. Flood than we're presently aware of, and with Anita Dobson teasing reveals are coming, let's take some time talking about who we think this new character might actually be.

Mrs. Flood Is The Master

There are many times where Doctor Who presents a mystery and I'm immediately inclined to think The Master is somehow involved. I speculated he was who Neil Patrick Harris' was playing in the 60th anniversary before it was revealed he was actually The Toymaker, and I'm doubling down and assuming Mrs. Flood is now The Master in disguise. Most of the reason I'm thinking this is because it's something I'd love to see happen, especially since we don't know what's going on with The Master following his defeat by the Thirteenth Doctor.

When the previous Master actor, Sacha Dhawan, was asked if he'd reprise the role when Russell T. Davies took over, he gave a cryptic response, and that has me wondering if he's still playing the character. If that's the case, then Mrs. Flood couldn't possibly be The Master... or could she? The Toymaker kept The Master concealed in a gold tooth and assuming it was Dhawan's incarnation, he would've regenerated, right? The Master covertly hid out as a human on Earth while hatching his last scheme, so who's to say that couldn't happen again?

Mrs. Flood Works For UNIT

Doctor Who's 60th anniversary brought back UNIT once again, and we'll see more of the organization in the next season. Jemma Redgrave's Kate Stewart is confirmed as part of the Season 14 cast list, so could Mrs. Flood be a UNIT operative keeping tabs on Ruby Sunday?

What exactly would be so important about Ruby Sunday that UNIT would need to keep an eye on her? In fairness, The Doctor's companions are often people who end up doing incredible things, so maybe UNIT already had an eye on Ruby because she has some big role in the world that not even The Doctor is aware of just yet. He may have an inkling considering he felt comfortable mentioning he was a foundling, which is a shared connection between Ruby Sunday and The Doctor, and he didn't even do that with Donna Noble.

Mrs. Flood Is An Alien Hiding On Earth

The Doctor has saved the Earth a countless number of times, and yet the human population at large seems to be oblivious to his existence. Alien species, especially those living in hiding on Earth, often tend to be in the know about The Doctor and his role as a protector of the planet. Perhaps Mrs. Flood is just an alien disguised as a human and positioned near Ruby Sunday's home for some specific reason.

If this were the case, why wouldn't Mrs. Flood reveal herself to The Doctor or try to help? Perhaps he's not meant to know about her presence just yet due to some timey-wimey stuff. It's also possible that perhaps she's hiding her knowledge of the TARDIS and other Doctor-related things because she's a potential enemy to the Time Lord or humanity. Wouldn't an alien ally want to make themselves known or useful?

Mrs. Flood is... The Doctor?!

To people who only recently rejoined Doctor Who with the 60th anniversary specials, this may sound bonkers. Those who stuck with the series through Jodie Whittaker's run, however, will remember the Timeless Child arc, specifically the wild reveal that Jo Martin's character was also The Doctor. How could The Doctor not recognize themselves? Well, it mostly was due to memory erasure, and without getting too deep off-topic, it's currently unknown how many times The Doctor regenerated before the incarnation we call the "First Doctor."

Could Mrs. Flood be a secret incarnation of The Doctor? I think it would be a bit odd for Russell T. Davies to recycle Chris Chibnall's big reveal so soon after he did it, so I'm doubtful. At the same time, it would be pretty cool to learn about another secret Doctor again, assuming there are plans to actually utilize her.

Mrs. Flood Switched Identities Mid-Special

This isn't really a theory in terms of who Mrs. Flood might be, but rather a theory on a strange happening during the Christmas special. When The Doctor first arrived to monitor Ruby, Mrs. Flood had no idea what a "blue box" was doing in front of her home. By the end of "The Church on Ruby Road," which is available to watch with a Disney+ subscription, she's fully in the know. What exactly happened there?

One interesting connection is that prior to the Goblin's interference, Mrs. Flood is unaware of everything happening. After The Doctor is successfully able to go back in time and rescue Ruby from the Goblins, Mrs. Flood is seemingly aware of who The Doctor is and what a TARDIS is. Is it possible that she was replaced by another person posing as her in between those changes? It seems possible, and even if I'm wrong, I think this is a connection we shouldn't be ignoring when it comes to figuring out what the mystery is with Mrs. Flood.

More information on Mrs. Flood might be coming when Doctor Who returns with Season 14 on Disney+ this spring. I know that I'll have an eye peeled for more clues on her true identity and for whatever unexpected surprises may come along the way.