The latest episode of Doctor Who, "Can You Hear Me?," reintroduced a classic enemy called the Eternals - but also retconned their history and powers. Doctor Who season 12 has been a strange beast, with most episodes so overstuffed with ideas that could do with being turned into two-parters; "Can You Hear Me?" is just the latest example.

The plot saw the Doctor and her fam stumble upon a powerful being named Zellin, a parasitic entity who was secretly manipulating them into freeing his fellow Eternal, Rakaya. Zellin's plan is successful, and the two Eternals head to Earth, intending to feed upon the worst fears and nightmares of humanity for the rest of time. Fortunately, of course, they've underestimated the Doctor - who is just a little bit cleverer than they thought, and turns their own "technology" against them.

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The Eternals are actually a fascinating deep cut into Doctor Who lore. But what makes "Can You Hear Me?" particularly interesting, though, is that the episode absorbs a lot of ideas and concepts developed in tie-in novels back before Russell T. Davies brought Doctor Who back to the small screen. As a result, it unwittingly retcons over 50 years of Doctor Who history. All the retcons make sense - that's why they were done in the books in the first place - but it's quite surprising to see them integrated into Doctor Who's official canon in this way. Let's examine the Eternals, and then explain the various retcons.

Who Are The Eternals in Doctor Who?

Doctor Who Enlightenment

The Eternals were introduced in the Peter Davison era of Doctor Who, in a 1983 story called "Enlightenment." This adventure saw the Doctor stumble upon a competition between ageless, immortal beings who were seeking true wisdom. Scriptwriter Barbara Clegg was inspired to create the Eternals when some distant family members visited her; they treated her and her family almost like "lesser beings," and craved perpetual entertainment. In the exact same way, the Eternals were presented as bored by their immortality, desperately seeking something to stave off their never-ending ennui.

In "Enlightenment," the Black and White Guardians - the greatest protectors of time, more powerful than even the Time Lords of Gallifrey - had persuaded the Eternals to compete in a sort of sailing competition in space, where their vessels rode the solar winds. The prize was Enlightenment itself, likened to the wisdom to know everything it's possible to know. Ironically, the Doctor contended this was a prize the Eternals could never actually acquire; because its true meaning was the power to choose, which his companion Turlough demonstrated, and the timeless Eternals lack that capacity.

Doctor Who Season 12 Reveals The Eternals Feed On Fear

Doctor Who Eternals Smile

At first glance, Doctor Who season 12 appears to hew closely to the original lore. Zellin and Rakaya are portrayed as powerful beings who enjoyed the thrill of being worshiped as gods, and who orchestrated cosmic games that brought two inhabited worlds into conflict. The inhabitants of these worlds figured out what the Eternals really were, and they successfully trapped one of them; it's not explicitly stated, but "Can You Hear Me?" implies the two races from this world sacrificed themselves. Zellin, completely lacking any creative thought himself, was unable to figure out how to free Rakaya; he had to trick the Doctor into doing it for him. So far, this accurately represents the original Davison-era story.

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But there is one important, and subtle, difference; "Can You Hear Me?" reveals the Eternals feed on the emotions of ephemeral beings. Thus Zellin has spent countless millennia harvesting the fears of humanity in order to keep Rakaya alive. It fits perfectly with a line of dialogue from the Peter Davison era - the Fifth Doctor called the Eternals "parasites" but never really went into detail - and it's lifted straight from tie-in novels. But this is significant, because it suggests even Eternals can cease to exist; they can be starved to death. "Can You Hear Me?" ends with the Doctor successfully trapping both Zellin and Rakaya in the ancient prison. There, they will presumably die, no longer able to feed.

The Celestial Toymaker Was An Eternal

Doctor Who Celestial Toymaker

A single line of dialogue in "Can You Hear Me?" links the Eternals to another classic Doctor Who villain, the Celestial Toymaker. "The Eternals have their games, the Guardians have their power struggles," Zellin observes. "For me this dimension is a beautiful board for a game… the Toymaker would approve." He's referring to a being encountered by the First Doctor in the 1966 story "The Celestial Toymaker," in which the TARDIS crew was stranded in another dimension and forced to amuse another immortal being. According to Doctor Who script editor Donald Tosh, the creative team had originally intended the Toymaker to be one of the Doctor's own race - the Time Lords had yet to be created as a concept - but this was dropped.

Now, at last, the Celestial Toymaker has an origin story of his own; he is another Eternal, who - like the rest of his kin - feeds on the emotions of others, and enjoys manipulating lesser races for sport. Again, this retcon is lifted straight from tie-in novels and audiobooks, which have generally been considered apocryphal - but now seem to be exerting a surprising influence on Doctor Who's canon.

Eternals Are Still Active In The Galaxy

Doctor Who Eternal Hands Raised

Given these beings are so powerful, and so ruthlessly amoral, why hasn't the Doctor encountered them more often? BBC's official companion book, A Brief History of the Time Lords, suggested the Eternals had been affected somehow by the Time War between the Daleks and the Time Lords. This fits with the Christopher Eccleston era, and the Doctor's encounter with a race called the Gelph in the episode "The Unquiet Dead."The whole universe convulsed," a representative of the Gelph observed. "The Time War raged. Invisible to smaller species but devastating to higher forms.A Brief History of the Time Lords implied the Eternals had retreated from this plane of existence altogether, presumably in an act of self-defense.

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It's possible Zellin and Rakaya are the last of the Eternals in this universe. Rakaya may well have been trapped before the Time War, and Zellin thus remained to keep her alive, unwittingly cutting himself off from the rest of his race as they fled this plane of reality. If that's the case, then the Doctor isn't going to meet any more of them ever again.

The Eternals May Have Been Time Lord Gods

Doctor Who Jodie Whittaker

Zellin's introduction leaves the Doctor shaken to the core; she recognizes his name as that of a supposed deity. But the scale of the Doctor's reaction is a little surprising, given this is hardly the first time she's learned a superstition has its roots in a species like the Eternals. Zellin seems a lot more personal - as though he were an ancient Gallifreyan god. This isn't the first time Chris Chibnall has hinted at Time Lord religion, with Doctor Who season 11 introducing a Time Lord creation myth in the Solitract. Again, this concept - although only implied - is lifted straight from the novels.

It's possible this isn't a coincidence; Doctor Who season 12 is promising to rewrite the show's lore, with the Doctor currently investigating the mystery of the Timeless Child, a secret from the dawn of Time Lord civilization that's been carefully concealed. Chibnall has a co-writing credit on "Can You Hear Me?," perhaps hinting this story is more important to season 12's overarching narrative than currently seems to be the case.

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