UNIT is providing security cover at an experimental drilling project designed to penetrate the Earth's crust and release a previously untapped source of energy. Soon however the drill head starts to leak an oily green liquid that transforms those who touch it into vicious primeval creatures with a craving for heat.
The Doctor tries to use the energy from the project to repair the TARIS console, but in doing so he is accidentally transported to a parallel universe, a world which is a little more advanced than our own. He encounters his friends' ruthless alter egos.. The Doctor has a race against time to save both universes.
Join us for the classic adventure from 7.30pm and pressing play at 8pm GMT