The Edge of Destruction/The Pilot
At Coal Hill School, teachers Ian Chesterton and Barbara Wright have concerns about pupil Susan Foreman, who has an alien outlook on England. When the teachers visit her address to investigate, they encounter a police box and hear Susan’s voice inside. An old man arrives, but refuses to let the teachers inside the police box. They force their way inside to find Susan in a futuristic control room that is larger than the police box exterior. Susan explains that the object is a time and space machine called the TARDIS and the old man is her grandfather. The unnamed old man, whom Ian and Barbara refer to as The Doctor, says that he and his granddaughter are wanderers in the fourth dimension, exiled from their own planet. Refusing to let Ian and Barbara leave, The Doctor sets the TARDIS in flight and ends up in the Stone Age.
The Edge of Destruction
The First Doctor, while attempting to correct the TARDIS’ faulty navigation circuits, causes a small explosion. The Doctor, Barbara, Ian, and Susan are all temporarily rendered unconscious. When they wake, Ian and Susan appear to have slight cases of amnesia and everyone begins to act strangely. The travellers are becoming suspicious of each other’s motives, and the Doctor accuses Ian and Barbara of sabotage. Fearing that they have been taken over by some alien force-or that they have intentionally sabotaged the TARDIS to force The Doctor to return them to 1963-he drugs Barbara and Ian, unknowing that Ian is also suspicious and has not taken the drink given to him. The Doctor attempts to explore the problem without interference.
Gradually it becomes clear that the strange events are an attempt by the TARDIS itself to warn the crew that something is wrong. Barbara’s clue gathering forces The Doctor to trace the problem to a broken spring in the Fast Return Switch. The malfunction is causing the TARDIS to head back to the beginning of time, the strange events were just attempts by the TARDIS to warn the passengers before the ship is destroyed. Fixing the switch brings all back to normal. Although the day is saved, Barbara is still affected by The Doctor’s harsh words earlier. The Doctor apologises, and admit that he was wrong about Barbara and Ian. The story closes with the TARDIS materialising on a snowy landscape, where Susan spots a giant footprint in the snow.