With the fast tracked script, also came the time sensitive nature of filming. Due to budge restrictions, most episodes were allowed only one take. William Hartnell was gradually succumbing to the disease which would eventually rob him of his memories. Viewers may notice when he ad libs, throwing the other actors off the script. Within this episode he repeats a few lines and completely forgets to tell the audience why the clocks were malfunctioning. A geeky trivia note also sees the switch labels on the console of the TARDIS in felt tip pen!.
It becomes evident to everyone on board that the strange things happening stems from the TARDIS itself. The Doctor scoffs at the idea that the TARDIS is a living being (fast forward to “The Doctors Wife” to find out more about that idea!)
The Doctor begrudges the assistance Barbara continues to give, but is forced to see that her fact finding leads them to the real problem the TARDIS is having.
Before they landed on the Dalek planet, the Doctor had initiated the ‘Fast Return Switch”; but it hadn’t worked. He looks only to find that the spring has snapped. This tiny malfunction sees the TARDIS and its crew veering into the beginning of time. The TARDIS was only trying to warn the passengers to the impending danger.
The Doctor fixes the spring and disaster is once again averted. He is then forced to apologise to Barbara and agrees that he has been wrong about humans.
The TARDIS lands, opening up into a snowy field marked with huge footprints.