10 Doctor Who Fan Theories That Will Blow Your Mind

10. Nardole Is Dorium Maldovar

One of the Twelfth Doctor's primary companions in Series 10, Nardole was first introduced in the 2015 Christmas special. From his first appearance to his last, we never really learned too much about the character, with most details about his history coming in the form of throwaway lines and jokey comments.

A couple of these comments included the fact that Nardole hasn't seen his real face in years, because he once swapped it for his current one while "on the run", and also, that he used to be blue. If combined, these two oddly specific details seem to hint at a link between Nardole and Dorium Maldovar, a blue, bald, black market dealer who first appeared in Series 5's The Pandorica Opens.

In Series 6, Dorium returns again, losing his head while fighting the Headless Monks in episode seven. This is possibly where Nardole's comment about swapping faces comes into play; since Dorium's body lacked a head, he could have slotted a new one on (the one Nardole has now) somehow. In addition, Dorium is fat and bald - just like Nardole - and he's also blue, a colour Nardole claims he used to be.