Doctor Who's biggest season 14 mysteries from Mrs Flood to Ruby's mother

The BBC show returns on May 11 and there are several questions that need answering in future episodes

Neil Patrick Harris, Ncuti Gatwa, Millie Gibson and Anita Dobson in the Doctor Who Christmas specials
Doctor Who returns for season 14 in May, and there are several mysteries to be revealed in coming episodes. (BBC)

Doctor Who is back for season 14 and more exciting than ever, and showrunner Russell T Davies has already set up a number of big mysteries for viewers to ponder over while they wait.

The showrunner returned to the BBC franchise ahead of its 60th anniversary in November 2023, and he laid the groundwork for different intriguing questions within these three specials, and the Christmas special that introduced Ncuti Gatwa and Millie Gibson as the Fifteenth Doctor and companion Ruby Sunday.

Read more: When does Doctor Who series 14 start on TV?

As time goes on, these moments and storylines will no doubt become an important factor to the Time Lord during his adventures. The question now is how, and why? Let's dig into them all to figure it out.

Anita Dobson as Mrs Flood in the Doctor Who Christmas special
Mrs Flood is played by Anita Dobson, who broke the fourth wall in the Christmas special. (BBC)

The biggest mystery going into season 14 is the identity of Mrs Flood, played by Anita Dobson, who made an unexpected splash amongst viewers when she broke the fourth wall in the Christmas special, The Church on Ruby Road.

Mrs Flood caused a stir when she looked to the camera and asked the audience at home if they hadn't "seen a TARDIS before" in a mid-credit scene after she helped convince neighbour Ruby to join The Doctor on his new adventures.

Davies shared in Doctor Who: Unleashed that Mrs Flood's true identity will be a key question moving into season 14, with Dobson refusing to share any teasers about who the character could be and why she spoke directly to the audience.

There are several fan theories around who Mrs Flood could really be, one suggestion is that she's another Time Lord, or even The Master in disguise.

Ruby Sunday's birth mother in the Doctor Who Christmas special
Ruby's birth mother was seen as a hooded figure in The Church on Ruby Road. (BBC)

Another mystery moving into season 14 is the identity of Ruby's birth mother, who appeared as a cloaked figure in the Christmas special after leaving her infant daughter on the steps of a church.

The episode sees Ruby try and find her parents years later through Davina McCall's Long Lost Trace: Born Without a Family, but the presenter later informs her that there is nothing to identify her parents on any database around the world. There's no DNA evidence of either her mother or father in the system, begging the question of why this is the case.

One running fan theory is that Ruby's mother is someone important to the Doctor Who franchise, with several suggesting she is none other than Rose Tyler (Billie Piper). Some theorise that Rose could have had Ruby with her iteration of the Tenth Doctor in the alternate universe she lives in, but was forced to give the child up because of an as-yet-unexplained danger.

Ncuti Gatwa in the Doctor Who Christmas special
The Doctor watching Ruby at the start of the Christmas special. (BBC)

Another mystery from the Christmas special was a blink-and-you'll-miss-it moment early in the episode, which saw The Doctor watching Ruby whilst she played with her band over the festive period. At the time, Ruby was being terrorised by the goblins that fed off of coincidences but this doesn't appear to be the reason why the Time Lord is watching Ruby.

The scene sees Ncuti Gatwa's Doctor watching Ruby with a very serious expression, dressed in an outfit that he hadn't worn before and doesn't wear for the rest of the episode. Some fans have theorised that this moment is more significant than meets the eye, suggesting that the Doctor we are seeing is actually a future version of the character that has gone back in time — and for a reason.

The Toymaker's tooth in the Doctor Who Christmas special
The Toymaker's tooth where The Master has been sealed. (BBC)

Moving onto the 60th Anniversary specials, there were many key moments that will be significant because of the questions they raise in future episodes. The first of these is the most obvious, and that is the return of The Master.

The Doctor's (David Tennant) iconic archenemy was sealed away inside The Toymaker's (Neil Patrick Harris) golden tooth. The celestial being said the Time Lord's nemesis had begged for his life and played a final game to save it, which he lost — resulting in The Master being imprisoned. After the Doctor bi-generated and defeated The Toymaker, his golden tooth dropped to the floor and was picked up by a mystery person.

This, of course, suggests that The Master will return to the franchise very soon. Following the show's revival several actors have played The Master, namely John Simm, Michelle Gomez, and Sacha Dawan. It is unclear whether one of these actors will reprise the role, or if a new actor will be cast.

David Tennant and Neil Patrick Harris in the Doctor Who Christmas special
The Toymaker spoke of The One Who Waits whilst playing a card game with The Doctor. (BBC)

The Toymaker made for a brilliant villain against the Doctor in the 60th anniversary special The Giggle, but the character teased someone even more dangerous: The One Who Waits.

Harris' villain explained to the Doctor that The One Who Waits is a being even he refused to challenge over the years because of how powerful they are. He refuses to give away their identity and says that the character is "somebody else's game". In The Star Beast, The Meep also spoke of a "boss" which could well be the villain in question.

Davies has always enjoyed playing the long game when it comes to introducing villains to the BBC series, and it seems The One Who Waits is no exception. Fan theories around the character suggest that The One Who Waits is a celestial being that predates the universe, and the most likely candidate in Doctor Who lore is Fenric. Though it is also possible that the character will turn out to be someone new.

Catherine Tate and David Tennant in the Doctor Who Christmas special
The Doctor pours salt in Wild Blue Yonder. (BBC)

The concept of coincidences also appears to be significant moving forward, because there have been a number of references to them in both the 60th Anniversary specials and the Christmas special. It all began in Wild Blue Yonder, when Tennant's Doctor used salt to stop his and Donna Noble's (Catherine Tate) doppelgangers from crossing towards them, saying they had to follow the rules of the superstition.

This action has had a rippling affect on the series, because ever since this moment the series has focused on coincidences and what they could signify. The idea plays a major part in the Christmas special when it is revealed that the goblins terrorising Ruby feed off of coincidences.

With so much riding on this notion, it seems reasonable to believe that the show will continue to bring up coincidences and rely on them as a storytelling device. But why? Davies will no doubt have a plan in mind.

Nathaniel Curtis as Isaac Newton in the Doctor Who Christmas special
Isaac Newton in Wild Blue Yonder. (BBC)

A mystery that is less life-threatening than the rest is the concept of "Mavity", which came about purely by chance when The Doctor and Donna met Sir Isaac Newton (Nathaniel Curtis) and the scientist misheard the word "gravity" as "mavity", thus changing the name of his theory for the whole universe.

While it was played off as a joke it has actually continued to be referenced in the show, with Donna talking about mavity on several occasions and Gatwa and Gibson's characters also using the term instead of gravity in the Christmas special.

This could be something, it could be nothing, but it is an intriguing mystery nonetheless and viewers are no doubt wondering how long the idea of mavity will be used in Doctor Who, and whether the mistake will ever be corrected in future.

Doctor Who series 14 returns on Saturday 11 May on BBC One, BBC iPlayer and Disney+.