Doctor Who has been a staple of weekend viewing since it came back on air in 2005. From Christopher Ecclestone to Jodie Whittaker, we have followed the Doctor on marvellous adventures - accompanying them as if we are one of the many companions we have got to know and love. However, there has been many twists and turns in the Doctor's story and it is no surprise that Chris Chibnall has carried on this tradition.
On Sunday 26 January 2020, we witnessed as Whittaker's Doctor comes face-to-face with, apparently, herself. In the climax of Series 12 Episode 5 'Fugitive of the Judoon', we witness the character of Ruth Jones, as played by Jo Martin, regain her memory and emerge as the glorious new Doctor. However, it may not be all it seems as Whittaker does not remember Martin and vice versa.
So, who is this mysterious Doctor and why does Whittaker not recognise her? And crucially, could she be a very familiar face from Who lore?
10. The Chameleon Circuit
We witness as Whittaker's Doctor realises why her sonic screwdriver could not uncover Ruth Clayton's identity - it was the Chameleon Circuit. The TARDIS's protocol of disguise had serves Martin as a form of camouflage. However, it might go further than just one disguise.
Just as Ruth Clayton is a disguise for this new Doctor, this new Doctor is a disguise for River Song. As seen within David Tenant's episode 'The Family of Blood', we see the Doctor hiding his identity in the form of a human. The changes to both his genetic signature and his personality are apparent. While the Tenth Doctor becomes a teacher of his time, River Song becomes the Doctor.
She adopts his mannerisms such as not answering questions and fast-paced thinking. There is nothing to say that the Chameleon Circuit cannot be used to disguise itself on multiple levels, and with the complexity of Doctor Who, we wouldn't put it past them to write it - crazier things have happened!