Looking for Barbara, the Doctor, Ian and Susan learn that they have been exposed to lethal doses of radiation. The travellers are confronted by the city's inhabitants - the Daleks! Show more
Fearful of a Thal attack, the Daleks force Susan to trick the Thals. Realising that the Daleks are planning an ambush, the four travellers try to escape and warn the Thals.
Pretending to be a Dalek, Ian finds that that he is trapped inside the casing. The Doctor, Susan and Barbara have no choice but to abandon Ian as the real Daleks arrive and attack.
The Doctor and Susan are once again taken prisoner by the Daleks. In the mountains, Ian, Barbara and the Thals must negotiate a vast chasm to reach the city.
The Thals and the time travellers attack the Daleks from all sides as the Daleks start the countdown to release deadly doses of radiation into the atmosphere.
