The Doctor is lost in time and space.
To bring him back some of his old companions have to work together. All of them have a piece of the puzzle. Donna Noble hid a clue about his location behind the biggest libary in the universe.
For those who don't know Doctor Who and Donna Noble:
Doctor Who is a British science fiction series produced by the BBC. The show is about the adventures of a mysterious and eccentric Time Lord known as the Doctor who travels through time and space in his time machine, the TARDIS (Time And Relative Dimension(s) In Space), which normally appears from the exterior to be a blue 1950s British police box. With his companions, he explores time and space, faces a variety of foes and saves civilizations, helping people and righting wrongs.
Donna Noble original was only a character for the Christmas special, "The Runaway Bride". However Catherine Tate's performance as Donna was so popular with fans that she was asked to return as a full-time companion for series 4. In order to save the universe from the evil alien race, Donna temporarily absorbs the Doctor's knowledge and power, but her transformation has a terrible side effect. Her human mind cannot handle the Doctor's knowledge and power, and she begins to lose her sanity. The Doctor is forced to erase Donna's memories of him and their adventures in order to save her life.
Status December 2023: Because of multiple problems this geocache series is a work in progress. I hope I can publish the rest of the caches in early 2024.