Doctor Who Finally Explains A 30-Year Old Mystery

The Doctor has had many lives over the centuries, but in 1989’s “Battlefield,” it was hinted that he’d had one that even he didn’t know about. The Doctor Who story saw Sylvester McCoy’s Seventh Doctor face a bunch of Arthurian knights from another dimension where magic trumps science. Curiously, these inhabitants of another world knew the Doctor as Merlin. The Time Lord even found a note from Merlin in Arthur’s spaceship, which was written in his own handwriting. Nonetheless, the mystery was left open-ended.

31 years later, though, and it’s finally been explained. BBC Books has just published new tie-in tome Doctor Who: The Monster Vault, pitched as the ultimate guide to the villains of the Whoniverse, revealing fresh facts about the Doctor’s worst enemies. In the entry on the Destroyer, a monstrous demon from “Battlefield,” the book at last clears up the mystery of how the Arthurians knew the Doctor as Merlin. Simply put, Merlin is the Doctor from their universe.

“In another universe, psychic energy prevailed and the laws of magic prevailed [over the laws of science]. Some legends said that there were still Lords on Gallifrey, but they were Lords not of Time but of Magic. There was also a Doctor who was exiled to Earth. He served at the court of King Arthur as his Magical Adviser and was given the name ‘Merlin.’… In this universe, Merlin had a great enemy, the equivalent of the Master: Morgaine.”

Over the years, the common theory became that Merlin was a future Doctor, with some fans hoping the series would eventually confirm this with a contemporary incarnation of the hero. The Monster Vault’s explanation makes much more sense, though. It’s also some clever mirroring of the Third Doctor’s era. While in his third body, the Doctor was exiled to Earth and served as scientific advisor to U.N.I.T., often battling the Master during this time. Meanwhile, his alt-counterpart aided King Arthur and fought Morgaine, a powerful sorceress.

Following “The Timeless Child” revelations of season 12, we might’ve wondered whether the Merlin Doctor was one of those incarnations of the Time Lord’s past that he wasn’t aware of, but now we know the wizard was actually from another universe. Maybe that’s the next big twist Doctor Who can introduce – who’s up for diving into the Doctor-verse in season 13?