The Planet is Skaro, home world of the Daleks.

The Daleks ore excavating in order to find and revive Davros, the mad, crippled, scientific genius who first created them. They hope that he will give them the scientific superiority to break the deadlock with their Movellan enemies.

Faced once more with the deadly and seemingly indestructable Daleks, the Doctor's wits and strength are stretched to their very limits ...

Accompanied by the newly regenerated Romana, the Doctor lands on a mystery planet intrigued by the evidence of drilling taking place there, deep underground. The discoveries he makes are chilling.

For the plant is Skaro and the Daleks are in charge of the operation. But just what are his old enemies searching for? And why? Perhaps the answers lie with the Movellans, a beautiful humanoid race led by Commander Sharrel. They are waging a war of their own with the Daleks and the situation is now at a stalemate. Should the Doctor tip the balance of power to aid the Daleks ultimate destruction? Or are the Movellans´ intentions no less sinister than the Daleks themselves?

Suddenly the Doctor finds himself enmeshed in a deadly battle which could result in destruction if the Universe itself as, once more, he summons the strength to face an all too familiar, timelessly evil adversary...

Originally transmitted September 1st - 22nd, 1979