Arriving on the barren world of Androzani Minor, the Doctor and Peri find themselves embroiled in a long running war,
fought between the ruthless Morgus and the sinister Sharaz Jek.
At the heart of the conflict is a substance called Spectrox - both valuable and deadly! The Doctor and Peri end up being
poisoned by the material, which is killing them slowly and painfully, and there is no cure.
With death just hours away, how far must the Doctor go in order to save his friend’s life?
The Doctor’s latest regeneration has proven more unstable than his previous ones. His two companions, Tegan and Nyssa,
try to help him recuperate on the tranquil planet of Castrovalva.
Adric has been captured by the Master, who is taking advantage of the Doctor’s weakened state to ensnare him in an
elaborate trap whose recursive nature threatens to destroy his mind.
As the Doctor begins to recover he realizes that the Master’s trap for Adric is even more intricate than he could have
imagined and that he will stop at nothing to gain his revenge over the Doctor.
The Doctor and Adric travel to Logopolis to repair the TARDIS’ chameleon circuit, not knowing that a shadowy watcher is
spying on him.
Meanwhile, his old enemy the Master has only recently gained secure longevity by possessing the body of Tremas, and revels
in his safety. He has plans of his own for the planet of mathematicians, Logopolis, and a plan that could spell doom for
the entire universe.
Could this mean the unravelling of the causal nexus and the end of the universe itself?
The Doctor must pit his wits against the Master in a desperate battle to thwart his plans. But he is aware that this might
be a fight which could easily spell the end of his life.
Trouble is brewing once again; a series of robberies are taking place which seem linked to plans for a top secret
disintegrator gun. All evidence seems to point to the culprit being a sentient robot, created by an eccentric professor
and owned by a think tank.
However, the robot’s basic programming prevents him from killing, providing a contradiction to the clues.
At the same time, the Doctor is recovering from his latest regeneration; can he regain his senses and help UNIT solve the
case before time runs out?
The blue crystal that the Doctor took from Metebelis 3 in a previous adventure (The Green Death) is desperately sought
by the Eight Legs, a race of super mutated spiders, as the final ingredient in their plan for transforming the Great One
into the Supreme Being.
With help from an old mentor, the Doctor realizes the only way to foil the spiders is to face his fears and make the
ultimate sacrifice. The Doctor must risk death to return to the cave of the Great One and save the universe.