During an escape from the Daleks on Skaro, the TARDIS' space-time locator is damaged. The Doctor cannot accurately pilot the TARDIS. He is happy when it lands and decides to rest for the night before exploring his new surroundings. The following morning, the Doctor finds the ground of this world is made of metal and there is a strange, throbbing hum in the air. As he investigates the metal terrain, a huge robot (later identified as a Grukker) almost runs him over but he is rescued by unseen persons and loses consciousness.