Noor Inayat Khan

Noor Inayat Khan was a British spy stationed in Paris in 1943.

Biography
Khan encountered the Thirteenth Doctor and Ada Gordon, who had been transported through time by the Kasaavin. She allowed them to hide under the floorboards in her apartment while 's Nazi officers searched for the Doctor.

When the Doctor confronted the Master on the Eiffel Tower, Khan sent a message to London in morse code, allowing the Master to be mistaken as a British spy. (TV: Spyfall) It read "Officer O is a double agent, beware. He is not all he seems." (GAME: Crack Noor's Code)

Khan briefly travelled with the Doctor and Ada to Britain in 2020 (whereupon Team TARDIS, her regular companions, asked if they were "being replaced") before being returned to her own time and having her memories of the Doctor erased. (TV: Spyfall) Graham O'Brien later discovered that Khan, betrayed to the Nazis, "didn't live to see the end of the War". (PROSE: History's Finest)