The barren planet Exxilon, some time in the future. The TARDIS is forced down by a total power failure and the Doctor and Sarah meet a stranded Earth crew who came here to mine for priceless medical supplies. But what is causing the power failures? And why have the Daleks come here too?

The Doctor and Bellal continue to penetrate the City's defences while Sarah and Jill try to stop the Daleks leaving with the parrinium.

While the Doctor carries out an investigation into ESP, Mike Yates asks Sarah to look into some strange goings on at a meditation centre he's attending.

K'Anpo persuades the Doctor he must face his fear and return the crystal to the Great One.But first they need to get past Barnes and his men.

The storm-lashed planet Karn. Near a graveyard of crashed starships, the demented surgeon Solon hides in his castle, the last acolyte of the Time Lord despot Morbius. He only needs one final item to make his master live again... and then the Doctor and Sarah arrive...

The Doctor is captured by the Sisterhood, and Sarah Jane is blinded freeing him. The Doctor has no choice but to go back for a cure, unaware that he is leaving Sarah Jane in the hands of a treacherous Dr. Solon and the renegade Time Lord Morbius.

While the Doctor goes to confront the Sisterhood to seek a cure for Sarah Jane's blindness, Solon realizes that he must transfer Morbius' brain into a new body before it is too late.

Morbius lives once more, but as a rampaging beast. The Doctor is forced to ally with Dr. Solon to bring him to heel, but the two disagree about what should happen to Morbius.

Planet Zanak, unknown time. The Doctor and Romana are seeking the planet Calufrax where the second segment waits. They are in the right place and the right time… but on the wrong planet.

The Doctor begins to investigate the mysteriously wealthy planet Zanak. Mentiads, a deranged Captain, strange omens, miraculous mines – what does it all mean? And what does it have to do with the Key to Time?

The Mentiads take the Doctor, Romana and Kimus to a reunion with K9 and Mula, where they set about trying to defeat the Captain.

The Captain and Xanxia work toward their secret goals. Both depends on the pirate planet consuming one more victim - Earth.