Five Thousand Year Diary

The Five Thousand Year Diary was a journal kept by the Thirteenth Doctor. (GAME: Lost in Time)

It was an updated version of the Two Thousand Year Diary, (TV: The Girl Who Died) which was a later edition of the Twelve Hundred Year Diary, (TV: The History of the Doctor) which was, in turn, a continuation of the Nine Hundred Year Diary, (TV: Doctor Who) which followed up on the recently regenerated Second Doctor's Five Hundred Year Diary. (TV: The Power of the Daleks et.al.)

At some point after landing on Mars along with Dan Lewis and Yasmin Khan, they encountered and introduced themselves to an Ice Warrior, who recalled a history with someone called "The Doctor", which the Thirteenth Doctor said she wanted to record in her diary. (GAME: Lost in Time)