The TARDIS suffers a power drain and is forced to land on the planet Exxilon. Sarah is captured by the primitive inhabitants and the Doctor comes face to face with his oldest enemies.
The Daleks weaponry is rendered useless by the power drain and they're forced to make a truce with the Doctor and the members of the expedition from Earth.
The Daleks force the Exillons into slave labour to mine the life saving Parrinium. The Doctor and Bellal brave the puzzles and traps of the Exxilon city.
The Doctor and Bellal arrive at the centre of the Exxilon city, but the Daleks are preparing to depart and launch a deadly plague missile that will kill everyone left behind.
