10 Most Ridiculous Doctor Who Rumours Ever
9. The First Doctor Is Inside The Vault
The big mystery at the heart of Series 10 revolved around an enormous underground vault that the Doctor was guarding. The actual contents of this vault were kept a secret until the episode Extremis, which revealed that it contained Missy. But up until we learned this truth, all kinds of rumours spread within the fanbase.
Some people speculated that the vault held Captain Jack, Susan Foreman, or even the Thirteenth Doctor, however, one rumour that actually had some evidence backing it up was the idea that the vault contained the First Doctor, as played by David Bradley.
This partly stemmed from an interview with the actor - which took place months before he was confirmed to appear in the 2017 Christmas special - in which he strongly hinted that he was about to appear in Doctor Who.
The Doctor definitely has shades of darkness about him (especially Peter Capaldi's grumpier Twelfth Doctor) but the idea of him locking up a past incarnation of himself just sounds completely implausible, and a little bit insane to boot.