FindTheDoctor (series)

#FindTheDoctor was an alternate reality game (ARG, for short) that began releasing content in late 2021 as a promotion for the forthcoming Series 13. The ultimate goal was to determine the password to a hidden page on the official Doctor Who website. Each clue held a single letter that was highlighted in some way, as well as a hint towards finding the next clue. As of August 2021, it's presumed that the highlighted letters will form the password, though that is not yet confirmed.

Clue content was a mixture of online and real-world items, though the real-world items had some online form of record - presumably to aid fans who could not travel to them.

Clues

 * 1) The first clue was hinted at in the Series 13 trailer released on the Doctor Who YouTube channel on 26 July 2021. The video had a very faintly written "/mystery" at the bottom of the screen, leading to a web page on the Doctor Who website, which revealed the first clue as  D , in the word hidden in the welcome message, and hinting that it begins: 13:13.13.
 * 2) On 13 August, posted at precisely 13:13 BST, the next clue was released on the same web page as the webcast A message from Yaz. The video ended with the text "The next clue is coming soon", with the  C  coloured red. The text accompanying the video on the page also had "C" capitalised.
 * 3) The third clue came on 16 August with a promotional image from upcoming series, which was posted exactly at the time 13:13 and held a set of graffitied co-ordinates for Yaz's Park Hill flat in Sheffield. The number  5  in the co-ordinates was coloured green, giving it away as the next clue.
 * 4) The fourth clue was gained by following the co-ordinates of the previous clue, where a Google Maps Park Hill photo from 3 August (uploaded by a user called "John Smith" as part of John Smith's Google Maps reviews) contained a TARDIS that had "FIND ME 14/07" graffitied on it. The  E  was uniquely coloured red, making it the fourth clue. The photo is dated 13 February 2018, presumably the creation date of the file before being edited and posted, as the file name is "3973 Doctor Who 0102 Ep4_working_1a" and location shooting was recorded on that date for Series 12.
 * 5) The fifth letter was obtained by finding an Instagram post from 14 July, from the Doctor Who account, which depicted the Doctor holding up a piece of morse code reading "Liverpool Gallery". The letter  G  was highlighted.
 * 6) Indeed, at the Liverpool Gallery a painting entitled La Boîte Bleue showed a landscape featuring the TARDIS and an anachronistic rocket and landing module in the 1860s. The letter  Y  was capitalised, making it the sixth clue.
 * 7) On 20 August, "John Smith" left a 5-star review for the Science Museum, stating to have forgotten something there. The rocket and lander module in the painting is also found there. An exhibition at the museum was called Unknown object—RHCTDM-OEI-OLOAW/0209 --an anagram of "DOCTOR-WHO-EMAIL and "0209" representing the date "2 September"-- and was a display of the Thirteenth Doctor's sonic screwdriver, with the letter  V  capitalised in its accompanying text.
 * 8) Indeed on 2 September, the "Doctor Who Newsletter" send an email which contained a series of capitalised letters, forming the anagram BHIRLRIATIYBRMASRY, which, if rearranged, was BRITISH LIBRARY MARY. Mary Shelley's page on the British Library website had the letter  A  capitalised in the bolded word "reach".
 * 9) Shelley's page at the British Library contained the words "re A ch", "librarian" and "Doctor" highlighted in bold. Using the "reach.librarian.doctor" word combinations on What3Words lead to the National History Museum coordiates. The Museum had a page titled An almost complete mystery about the item called "EPDUPSXIPNBH-TFQU" —-a caesar cipher of "DOCTORWHOMAG-SEPT"-- which had  N  capitalised in the text description.

On mobile devices, the "/mystery"-page was also found to contain a hidden instance of the word "FRED", which was almost the nickname the Fourth Doctor gave Romanadvoratrelundar. Curiously, the "Inspect Element" password for the page is "X4G6H66TZ114Z33H19K6", which holds the exact amount of letters as the Time Lord’s full name. It is a matter of debate as to whether any of the two are separate clues or part of the final password.