For more than six decades, Doctor Who has taken viewers across time and space.
But hidden within the show's history are unfinished episodes recorded in Cambridge.
In 1979, production teams arrived in the university city following a storyline called 'Shada', written by local author Douglas Adams - featuring Tom Baker as the fourth Doctor.
However, not everything went smoothly during the shoot.
Speaking on a new BBC Sounds documentary Doctor Who: Lost in Cambridge, Marcus Hearn said his father, who was a porter at Clare College, saw first-hand some of the challenges the crew and Baker faced while filming.
The Doctor Who Magazine editor said: "Tom Baker had been struggling to learn how to punt and he kept falling into the Cam.
"It was my dad's job to provide him with blankets and brandy, and to basically try to calm him down because apparently he was in a very bad mood."