When returning showrunner Russell T. Davies takes back the keys to the TARDIS, he won't need to revisit Doctor Who's Timeless Child arc -- in fact, he should abandon it, and here's why. Davies inherits a mess of a story with no easy outs, unless departing showrunner Chris Chibnall has an unexpected ace up his sleeve. However, tigers don't change their stripes.

The season 12 finale revealed that The Doctor was the Timeless Child hinted at ever since Jodie Whittaker regenerated onto the scene. The Timeless Child mystery revolves around the idea that a mysterious child traveled to this universe through the Boundary - a dimensional portal that crosses the divides of existence. That Timeless Child became the source of regeneration, the ability for those from Gallifrey to change appearance and personality when facing imminent death.

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Whittaker officially plays the Thirteenth incarnation of The Doctor. However, the Timeless Child throws that concept out the window, instead suggesting that an infinite number of Doctors came before the one known as the first: William Hartnell. On paper, that shocking twist might have merit, but the subpar execution of Doctor Who's Timeless Child arc hindered the concept's success, messed with the overarching continuity of Doctor Who's entire timeline, and, thus, should be abandoned. Here's why.

The Timeless Child Is No War Doctor

Jodie Whittaker and John Hurt as The Doctor on Doctor Who

Steven Moffat, who proceeded Chibnall as showrunner, did something similar for Doctor Who's 50th Anniversary by capitalizing on the fact that the regeneration into Christopher Eccleston's Doctor had never appeared on the screen. He added a secret Doctor - The War Doctor played by John Hurt - between 8th Doctor Paul McGann and Eccleston's Ninth, which became the incarnation who fought in the mythical Time War. Chibnall's Timeless Child arc wanted to do the same but shot itself in the foot.

The problem with repeating an iconic retcon device in a nearly 60-year-old series is that it needs to be better than what came before, and Timeless Child isn't. In the capable hands of Moffat, Doctor Who did something that made viewers' heads explode not only because it changed everything they thought they knew but also because it fits perfectly within the constraints of established history. The Timeless Child instead sets off a bomb of continuity explosions across the entire timeline.

The Regeneration Of River Song Raises Too Many Problems

Alex Kingston as Child of the TARDIS River Song in Doctor Who

River Song developed her regeneration capabilities because she was conceived inside the time vortex while Amy and Rory traveled aboard the TARDIS. If The Doctor's genetics paved the way for Gallifrey's secret to longevity, then what gave River her regeneration cycle? It's an essential question because River Song isn't a one-off Doctor Who character: she has appeared across multiple Doctor eras. Unraveling her story isn't the most fantastic idea.

RELATED: Doctor Who's Timeless Child Retcon Broke River Song's Origin

Reconciling both the Timeless Child story and River Song's story leads to only one solution: The Doctor's people traveled the time vortex, too, and they may even live there. Either way, where were they during the Time War? Like River Song, the Time War weaves throughout Doctor Who canon, and pulling its thread unravels everything. If the Doctor's people were time travelers with regeneration capabilities, doesn't that make them Time Lords, too? Both species have two hearts, after all. Chibnall appears to have written himself into a corner, and a universal reset button seems unlikely.

The Name Of The Doctor And The Time Of The Doctor Make No Sense

Matt Smith Jenna Coleman John Hurt in Name of the Doctor and Time of the Doctor on Doctor Who

Doctor Who's 50th Anniversary wasn't just one episode. It was three. Preceding "The Day of the Doctor" was the finale to season 7, "The Name of the Doctor," in which Jenna Coleman's Clara threw herself into The Doctor's time stream. Now, it's one thing to say that The Doctor doesn't remember what came before, but it's quite another thing to claim that The Doctor's time stream only included remembered history. Clara met every one of The Doctor's faces, including the hidden War Doctor. If The Thirteenth Doctor had infinite lives proceeding The First Doctor, Clara would have met them, too.

The third installment of the anniversary trilogy - "The Time of the Doctor" - featured Matt Smith's Eleventh Doctor passing the baton to Peter Capaldi. In that episode, The Doctor required an entirely new regeneration cycle from the Time Lords to survive and defeat the Daleks. Only he didn't. If The Doctor is the source of regenerations, he should have been able to regenerate without assistance. Could a Timeless Child Doctor even die? He could've outlived all of his enemies simply by staying on Trenzalore and regenerating until they all died out. The Time Lords could've waited to hear the question, too.

Doctor Who Already Has A Mystery To Solve And It's Right In The Title

Doctor Who Companion Clara Learns The Name of the Doctor in Journey to the Center of the TARDIS

Timeless Child tries to solve the false belief too much is already known about The Doctor. Therefore, a new mystery requires implementation. Yet, nearly sixty years since its inception in 1963, The Doctor's name remains unknown, except to River. That implies a lot of mystery left for exploration before blowing everything up. Doctor Who? The oldest question in the universe, hidden in plain sight. However, the real question here should simply be, "Why?"

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Why isn't The Doctor's name known? What's the story there? Clearly, there is one since The Doctor's gone to such great lengths to keep it hidden. The actual name never needs telling, but the mystery of why The Doctor's kept that secret for so long could be pretty compelling. How did River find it out? Did Susan know what it was? Before tearing down everything The Doctor ever knew about her own identity, it would have been nice to learn why she'd been hiding it in the first place. Maybe instead of revisiting The Timeless Child, Davies could set his sites on the show's primary mystery heading into Doctor Who's diamond anniversary season.

NEXT: Doctor Who Theory: The Doctor Has Rewritten Gallifrey's Past