Warning: This article includes MAJOR SPOILERS for Doctor Who season 15's finale!

cameos in the Doctor Who season 15 finale – that completely alters Time Lord mythology.

The entirety of the Rani’s plan centers around bringing Omega, a progenitor of the Time Lords, back from the Underverse so that she can retrieve his DNA. The reason why she needs that DNA is because the Spy Master’s genocide of the Gallifreyans had a different effect on Time Lords and Time Ladies off-planet than expected.

Doctor Who's Time Lords Being Made Infertile Totally Changes The Show's Future

The Doctor's Child Still Hasn't Been Born Yet Before They Became Infertile

The end of Doctor Who season 15 reveals that the Time Lords and Ladies aren’t fully extinct, which many Whovians suspected. Instead, the individuals who Spy Master didn’t kill off were hit by a wave that rendered them completely infertile. It’s described as a slow way to make them extinct. The characters discuss it with shocking casualty, considering the audience had no idea up until this point. This completely rewrites Time Lord history. It’s unclear how many Time Lords and Time Ladies still exist in the universe, but the Doctor now knows that they aren’t the last one out there.

However, the Time Lords being infertile also puts a hitch in the show’s future. The Fifteenth Doctor reiterates in Doctor Who seasons 14 and 15 that their child hasn’t been born yet. It seemed like Poppy might be a human-Time Lord hybrid, who could be Susan’s mother. However, the Doctor doesn’t end up being Poppy’s father, meaning the character still has to procreate at some point in some way.

The TV show also has another option which is already established and developed in the Doctor Who extended universe – Gallifreyan looms.

Additionally, the Rani’s plan to bring back Omega might not have worked out in her favor, but she is still probably determined to bring back the Time Lords and Time Ladies’ ability to procreate through traditional means. On top of that, the 60th anniversary special teased that the Master/Missy is out there somewhere. They were in a golden tooth, and someone with red nail polish took it. If the Master wants to procreate or continue the Time Lord species, they’ll run into the same issue of being infertile.

This raises serious questions about how Time Lords will reproduce going forward. Bi-generation was supposed to be a myth, but the Doctor and the Rani both underwent this process. As such, bi-generation could be the species’ new method of asexual reproduction, like amoebas. However, the TV show also has another option which is already established and developed in the Doctor Who extended universe – Gallifreyan looms.

What Gallifreyan Looms Are

Gallifreyan Looms Are Outlined In The Doctor Who Books And Big Finish Audio Stories

Fans of the Doctor Who extended universe have theorized for decades that the Gallifreyans in the TV show used to reproduce through looms, like in the books and audio stories. In the Doctor Who books and audio stories, Pythia curses the Time Lords at the end of the war, the Great Schism, making them infertile. As such, they had to find a new way to continue the species. To get around the usual methods of procreation, Gallifreyan looms are a method of procreation by a machine that uses Time Lord biodata and fluids to create a new Time Lord.

The Doctor’s granddaughter, Susan, was the last womb-born child of a Time Lord born on Gallifrey for quite a long time.

Each Great House on Gallifrey had its own loom and a specific number of offspring that they decided could be alive at any time. According to the Lungbarrow book, Time Lords from the same looms were not siblings but cousins, and many of them were born with fully grown bodies. In this case, they needed to develop mentally over time until their body matched up with their mind. However, other Doctor Who books reveal that loomed children exist, too.

Looms look very different from one another, though it’s unclear whether they look different across Great Houses or if multiple versions of looms exist. One description is a very clean frame with mesh made out of tiny chords, another includes silver strings, while a third is a breeding factory with vats of fluid from which Time Lords and Time Ladies are born.

There was a darker side to looming, though. The Book of the War implies that the Gallifreyans participated in eugenics behaviors with the looms, selecting which parts of biodata to include. This is reinforced by the fact that houses could choose whether or not a Time Lord would be born with two hearts through looming. What’s more, Rassilon had all the womb-born children murdered because they were seen as inferior. However, the curse of Pythia is eventually lifted.

How Time Lords Being Infertile Sets Up Looms' TV Debut

The Gallifreyan Looms Could Solve The Infertility Issue

The Time Lords being completely infertile after the Spy Master’s genocide makes it very easy to introduce the Gallifreyan looms. The Doctor or the Rani could find some ancient form of Gallifreyan reproduction technology. Alternatively, in the books and audio stories, other species, like the Sontarans and the Osirians, use similar looms for reproduction. The remaining Time Lords could take inspiration from other species, creating the Gallifreyan looms. In either circumstance, the introduction of the Looms on TV makes another age-old book theory about the Doctor actually plausible for possibly the first time ever.

One prevalent theory about the looms is that the Doctor was loomed using the Other’s biodata. The legend goes that the Other threw himself into the Lungbarrow House loom, and the Doctor came out. The Doctor even claimed to being loomed. Whovians have debated whether this theory is possible or not based on the TV show for a while.

In order for it to be true, the Doctor Who canon (which doesn’t include the extended universe) needs to acknowledge the existence of Gallifreyan looms. Even though many parts of the TV show contradict the idea that The Doctor is actually The Other, Doctor Who introducing infertile Time Lords and Time Ladies opens the door to looms, which opens the door to RTD or another future showrunner retconning the Doctor’s origin story for the umpteenth time to confirm the theory. It would take a lot of logic jumps and twists to get there, but it’s at least possible now.