Doctor Who 'Space Babies': Why is The Doctor alone in the universe?

A still image Doctor Who Season 1 (15th Doctor) in the episode "Space Babies."
The Doctor is back in a relaunched series with a fresh explanation on why he's the last of the Time Lords. (Image credit: Disney Plus/BBC)

"Space Babies," the first episode of the new "Doctor Who" season, introduces the Fifteenth Doctor (Ncuti Gatwa) and his new companion Ruby Sunday (Millie Gibson) to a spaceship full of talking infants — and a slobbering monster with some very icky origins.

But, in an episode packed with exposition about the Doctor's two hearts and his space-and-time-traveling TARDIS phone box — not to mention a few teases about Ruby's mysterious backstory — it's perhaps the Time Lord's references to being "the last of the Time Lords" that carry the most emotional resonance. Here we explain why the Doctor is alone in the universe. And if you're wondering how to watch Doctor Who, check out our Doctor Who streaming guide for how to tune in from anywhere.

Disney Plus

Disney Plus is now the international home of "Doctor Who." That means that viewers outside the U.K. can watch new "Doctor Who" episodes on the streamer — as well as the three David Tennant-starring 60th anniversary episodes, and Ncuti Gatwa's first full outing as the Time Lord, "The Church on Ruby Road". 

Episodes debut on Disney Plus at the same time they appear on BBC iPlayer.

What does the Doctor mean when he says he's the 'last of the Time Lords'?

Exactly that. As far as we're currently aware, the Doctor is the only resident of his home planet — called Gallifrey — currently alive across all of time and space. It's a state of affairs identical to the one experienced by the Ninth Doctor (Christopher Eccleston) when "Doctor Who" returned after a 16-year break in 2005 — though since then, Gallifrey has both come back from the dead and been wiped out for a second time.

Throughout the tenures of the Ninth and Tenth Doctors' (David Tennant was the 10th) in the TARDIS, it was believed Gallifrey had been destroyed in the Time War, an interstellar skirmish fought between the Time Lords and the Daleks. Just as "Who"'s most famous villains inevitably found their way back from oblivion, however, the Doctor's people also survived. So, having made a brief comeback in the Tenth Doctor's final adventure, "The End of Time" (2009/10), the Time Lords were officially saved in 50th anniversary special "The Day of the Doctor" (2013), when 13 incarnations of the Doctor teamed up to freeze Gallifrey in a pocket universe.

Related: Doctor Who companions ranked worst to best

Unfortunately, it wasn't a happily-ever-after ending for the Time Lords. When the Fifteenth Doctor tells Ruby Sunday in "Space Babies" that "It was a genocide and they died," he's referring to the actions of his Time Lord nemesis, the Master (then played by Sacha Dhawan), who killed everyone on the planet in season 12 finale "The Timeless Children" (2020). The subsequent detonation of the so-called Death Particle wiped out all organic life on the planet, making the Doctor and the Master the last known Time Lords in existence. (More on the latter to follow…)

If the Doctor is from Gallifrey, why does he say he was adopted by the Time Lords? 

The Doctor (Ncuti Gatwa) and Ruby Sunday (Millie Gibson) in Doctor Who's season 1 episode "Space Babies." (Image credit: Disney Plus/BBC)

This refers to a controversial new element of "Doctor Who" lore introduced in "The Timeless Children." There, it was revealed that the residents of Gallifrey haven't always had the ability to regenerate into a new body. 

Instead, we (and the Doctor) learned that Tecteun (Seylan Baxter) — a member of the Shobogan race who originally inhabited the planet — had discovered the so-called "timeless child" on another world. Tecteun adopted her and went on to add the kid's miraculous capacity to regenerate into the physiology of her people, creating the Time Lords in the process.

It later turned out that this mysterious child was the Doctor, effectively making them the progenitor of the entire Time Lord race.

Related: 5 actors who nearly played Doctor Who 

 Why are the Doctor's origins mentioned so often in 'Space Babies?' 

This is a major relaunch for the show on a new international streamer (Disney Plus), so the episode does a lot of heavy-lifting to explain key bits of the show's 60-year mythology. 

But there are also some significant thematic parallels. For example, the Doctor, the space babies and new companion Ruby — who, as a newborn, was found outside a church on Christmas Eve — were all abandoned, and have no idea who their parents are. Expect this to be a continuing theme throughout the new season.  

Related: The greatest Doctor Who villains ranked 

Have we really seen the last of the Time Lords? 

Ncuti Gatwa as Doctor Who in episode 1 "Space Babies." (Image credit: Disney Plus/BBC)

Although the Doctor explains in the new season's second episode, "The Devil's Chord," that "the genocide rolled across time and space like a great big cellular explosion," it's unlikely we've seen the last of them. 

Returning showrunner Russell T. Davies was wise to sideline Gallifrey back in 2005 — the vast "Doctor Who" canon can be intimidating to newcomers — and it's arguably equally beneficial to keep the Time Lords out of the way now. Like Daleks, Cybermen, Sontarans and Zygons, however, Gallifrey is so intertwined with the show's lore that we'd be surprised if it stays dead forever. Besides, now that the Doctor has teased the existence of other Time Lords known as the Bishop, the Conquistador, the Pedant and the Sagi-Shi, we'd really like to meet them.

As for the Master, he was last sighted on an imploding planet at the end of final Thirteenth Doctor (Jodie Whittaker) story "The Power of the Doctor" (2022), while the Toymaker later claimed he'd imprisoned the renegade Time Lord in his gold tooth. If he was anyone else we'd say he was doomed, but if "Doctor Who" has taught us anything, it's that the Master always finds a way. The bigger question, perhaps, is who might be playing them when they return.

"Doctor Who" streams on BBC iPlayer in the UK and Disney Plus elsewhere in the world. New episodes debut at 7pm ET/4pm PT on Fridays, and midnight on Saturdays in the UK. Our guide to watching new "Doctor Who" episodes explains more.

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Richard Edwards Contributor

Richard's love affair with outer space started when he saw the original "Star Wars" on TV aged four, and he spent much of the ’90s watching "Star Trek”, "Babylon 5” and “The X-Files" with his mum. After studying physics at university, he became a journalist, swapped science fact for science fiction, and hit the jackpot when he joined the team at SFX, the UK's biggest sci-fi and fantasy magazine. He liked it so much he stayed there for 12 years, four of them as editor. 

He's since gone freelance and passes his time writing about "Star Wars", "Star Trek" and superheroes for the likes of SFX, Total Film, TechRadar and GamesRadar+. He has met five Doctors, two Starfleet captains and one Luke Skywalker, and once sat in the cockpit of "Red Dwarf"'s Starbug.  

  • steve_foston
    Another twist to come, perhaps, the Doctor's grandchild Susan settled on Earth in the 1960's and presumably she is from Gallifray too - he storyline has been very quiet about her and her own children