Ah, so you’re my replacements. A dandy and a clown.
Certain Doctor Who stories stand out in the series because of their plots, others for their villains or their effects, for good or for ill. Season Ten opener “The Three Doctors” (Story Production Code RRR), by regulars Bob Baker and Dave Martin, remains remarkable due to the casting: all three Doctors to date, in the same place (mostly) at the same time. Beyond the surface conceit, however, “The Three Doctors” also occupies a special place in the series because Baker and Martin deepen the backstory of the Time Lords, giving viewers the clearest insight yet into this heretofore mysterious race of regenerating time travellers. Too, they inadvertently point out that the series requires a single strong lead figure, with companions relegated to an assistant role—too many Doctors spoil the soup.
Earth is once more in danger due to the Doctor’s presence on the planet, this time from exceedingly strong cosmic ray bolts that serve as a conduit from a gigantic black hole, depositing bulbous, shambling creatures with a predilection towards explosions, all of which are programmed to seek out the Doctor. The bolts work both ways, and before long several people (not to mention laboratory equipment and, eventually, a chalet) are scooped up and sent into whatever awaits in the middle of the black hole. OK, it’s a quarry at the other end, but it’s an anti-matter quarry sustained by the will of Omega, a revered hero of the Time Lords.
Once the Time Lords uncovered the secret of time travel, they still needed an energy source to power their actual travel through time. Omega, the foremost solar engineer amongst the ancient Time Lords, provided such power but was thought lost in the resulting supernova. Unbeknownst to the Time Lords, however, Omega instead remained trapped beyond the event horizon of a black hole, and through the sheer force of his will, he harnesses the power of the singularity at the heart of the black hole to create a pocket of matter in a sea of anti-matter. And there he has waited, for countless thousands of years, alone, the desire for revenge growing constantly.
To take his vengeance, Omega begins to drain the power from the Time Lords’ energy source, using the threat of their annihilation (and, coincidentally, that of the universe) as leverage to force the Doctor to take his place. Omega cannot escape unless a sufficiently powerful will remains behind to sustain the conduit. But because the Time Lords, in their desperation, violate the First Law of Time™ and cross the Doctor’s time stream not once, but twice. Omega has three Doctors with whom to contend—as does the Brigadier, who frankly thinks one is enough…