Summary

• Ruby Sunday in Doctor Who resembles Moffat-era companions by being mysterious from the off - more like Amy and Clara than Rose, Martha, and Donna.
• She is a mysterious character with questions about her birth parents and a potential connection to another Time Lord.
• Unlike previous mystery companions, Ruby's relationship with the Doctor is portrayed as platonic, avoiding unnecessary romance.

Ruby Sunday is the first Doctor Who companion to debut since Russell T Davies returned as showrunner, but Millie Gibson's character actually has more in common with the companions from Steven Moffat's era. Classic Doctor Who companions were infamously two-dimensional, only required to scream, run, and ask questions - not necessarily in that order. Since 2005, Doctor Who has endeavored to flesh out its companions into proper characters, with everyone from Rose Tyler to Yasmin Khan getting more characterization, backstory, and development during their time in the TARDIS.

Even in the modern era, however, Doctor Who companions have evolved. When Russell T Davies was leading the show's revival, companions were typically ordinary humans plucked from their mundane lives to travel through time and space. Rose, Martha, and Donna all came with colorful families and everyday problems - relationships, careers, poverty, etc. The Doctor allowed them to escape their Earthly woes and routines. Taking over Doctor Who in 2010, Steven Moffat ushered in a new style of companion that was almost the antithesis of his predecessor. Strangely, RTD's own Doctor Who season 14 now appears to be following Moffat's example.

Moffat-Era Companions Established Doctor Who's "Mystery Girl" Trope

Rose, Martha, and Donna each had their own profound impact upon the Doctor, but no larger mysteries surrounded those individuals when their respective runs on Doctor Who began. Each had a simple backstory, a clear role, and a humble standing in the universe. The RTD storyline that came closest to making a companion part of a wider cosmic event was Bad Wolf, but even that transpired only because Rose was unfortunate enough to be the Doctor's companion at that time. For the vast majority of her stint in the TARDIS, Rose was a regular girl - not a puzzle for the Doctor to solve.

During Steven Moffat's Doctor Who era, companions were inherently special even before the Doctor picked them up. Indeed, it was usually their special-ness that brought them to the Doctor's attention. Amy Pond's Doctor Who arc was first defined by the strange crack in her bedroom wall, then later by the revelation that her future daughter was the Doctor's wife. Amy's fate was woven into the Doctor's timeline before she even had a chance to say "it's bigger on the inside." Clara - actually nicknamed "The Impossible Girl" - proved even more of an enigma, with Matt Smith's Eleventh Doctor taking her as a companion mostly just to figure out why different versions of Clara Oswald were popping up all across history.

Whereas RTD companions were defined by being ordinary, Clara and Amy were defined by being extraordinary. Moffat toned down the "mystery girl" trope for his final full-time companion, Bill Potts, but even she became entwined with the otherworldly Pilot during her very first Doctor Who episode. Moffat's obsession with mysterious girls puts Peter Andre to shame, and it's telling that his successor, Chris Chibnall, reverted to RTD's Doctor Who companion mold. Yaz, Ryan, Graham, and Dan were all ordinary humans lucky enough to become the Doctor's friends, and none had any nagging question marks hanging over their individual existences.

Ruby Sunday Is More Like Doctor Who's Moffat-Era Companions

Ruby Sunday slots perfectly into the mold of a Steven Moffat Doctor Who companion, sitting naturally alongside Amy and Clara as an enigmatic young woman - from the UK, obviously - that straight away raises questions for both the Doctor and the audience. Firstly, Doctor Who's 2023 Christmas special knowingly planted intrigue over Ruby's birth parents. Left on a church doorstep as a baby by a shadowy cloaked figure, Ruby has been unable to find a trace of her biological mother and father. Since this is Doctor Who, the eventual reveal of Ruby's parents is almost certain to have alien implications.

Ruby Sunday becomes even more mysterious when taking her present-day circumstances into consideration. Ruby lives next door to Mrs. Flood - a potential Time Lord, given that she knows what a TARDIS is, but a pivotal figure within Doctor Who lore at the very least. Furthermore, the Goblins from 2023's Christmas special targeted Ruby because they feed on coincidence, according to Ncuti Gatwa's Fifteenth Doctor. There may have been deeper levels of coincidence at play than the Doctor was actually aware of here - Ruby being another Timeless Child, for example.

Doctor Who audiences entered the eras of Rose, Martha, and Donna with no big questions regarding the Doctor's latest traveling buddy. Doctor Who audiences entered the eras of Amy and Clara with plenty of big questions regarding the Doctor's latest traveling buddy. Ruby Sunday, despite being created by Russell T Davies rather than Steven Moffat, sits firmly in the latter camp.

Doctor Who Season 14 Is Avoiding The Biggest Problem With Moffat's "Mystery Girl" Companions

The mysterious companion trope Doctor Who peddled between seasons 5 and 8 came with one recurring problem - it encouraged romance where romance was not needed. The early days of the Eleventh Doctor saw Amy launching herself at the Time Lord's face, leaving poor Rory an afterthought. Doctor Who eventually realized its error, established Amy and Rory as a power couple, and set the Doctor up with their daughter instead - which sounds weirder, but worked better in context. Clara and the Eleventh Doctor were never explicitly romantic, but the emergence of an older-looking Twelfth Doctor exposed how Clara had always thought of Eleven as her "boyfriend."

The intrinsic ties the Doctor had with Amy and Clara looked deceptively like they would be good jumping-off points for romance. Alas, they were not, but the Fifteenth Doctor and Ruby are already avoiding that problem. Ncuti Gatwa has described the Doctor and Ruby's dynamic as, "We would've gotten in trouble at school. We would've been in the detention classroom together at school and still cackling." That sounds very much like a platonic, best-friend bond, and their first episode together, "The Church on Ruby Road," proved as much. This time, Doctor Who can reap the benefits of a long-term companion mystery without the awkward romantic overtones.