The Third Doctor and Sarah arrive in 1970s London to find it has been evacuated because dinosaurs have appeared mysteriously. It turns out the dinosaurs are being brought to London via a time machine to further a plan to revert London to a pre-technological level.
The Doctor returns to Peladon fifty years after his last visit, to find Queen Thalira, daughter of the late King Peladon, on the throne. A tense labour dispute between Pel nobility and miners is worsened when apparitions of their deity Aggedor attack and kill several miners. The Galactic Federation desperately needs trisilicate for its war against Galaxy 5 and sends in brutal Ice Warrior troopers to ensure production. The Doctor discovers a devious plot at the heart of Aggedor's appearances.
The blue crystal that the Doctor took from Metebelis III in a previous adventure is desperately sought by the Eight Legs, a race of mutated spiders, as the final element in their plan for universal domination. With help from an old mentor, the Doctor realises the only way to foil the plot is to make the ultimate sacrifice. The Doctor must risk death to return to the cave of the Great One and save the universe.
Alex Corvis, a man wrongly executed for the murder of his girlfriend, returns from the dead and sets out to find the real killer.
Super-soldier recruit Tsui Chik is forced to escape with his comrades after the project is canceled. Months later, he's trying to have a quiet life as a librarian with his best friend, Inspector Shek Wai-Ho. However, a string of vicious gangland murders begins that has all the markings of Tsui's former compatriots who seem to have turned to crime. Realizing that the police are helpless, he decides to take them on himself. With a disguise, Tsui becomes the mysterious superhero known only as Black Mask.
As the Doctor's trial continues, evidence is presented showing his most recent adventure, one where he faces an old adversary, Sil. As a scientist conducts his unethical experiments to prolong the life of Sil's boss Kiv, the Doctor's memories of the events begins to return and an unpleasant surprise awaits him.
The Doctor is summoned before the High Council of Time Lords to stand trial for the charges of harmful interference to the course of events during his travels which have threatened the sanctity of the universe. Indignant at these accusations, the Doctor pleads his case to the Inquisitor with the hope that she will see him as a source of hope and goodwill for existence. However, his prosecuting attorney, a sinister Time Lord known simply as the Valeyard, begins a crusade against the Doctor with the motive of framing him as a villainous renegade.
A race of giant Gastropods has taken over the planet Jaconda. Their leader, Mestor, now intends to cause an enormous explosion in order to spread his people's eggs throughout the galaxy, and he kidnaps juvenile twin geniuses from Earth to work out the necessary mathematical equations. Space fighters led by Lieutenant Hugo Lang are dispatched to get the twins back, but they come under attack and Lang is the sole survivor when his ship crashes on the asteroid Titan III. A newly regenerated Doctor and Peri become involved and help Jaconda's elderly former ruler Professor Edgeworth, who is really a Time Lord named Azmael, to defeat Mestor and free the planet's bird-like indigenous people from the gastropods' reign of terror. Azmael, however, sacrifices his life in the process.
At the Tranquil Repose mortuary, the Doctor and Peri uncover a sinister plot to create a new breed of Daleks under the supervision of the mysterious Great Healer.
The Doctor and Peri arrive on Karfel, a planet ruled by fear where the enemies of its ruler, the despotic Borad, are banished into a time tunnel known as the Timelash.
Suddenly gripped by a memory of being executed in his second incarnation, the Sixth Doctor travels to Seville to save his past self and ensure his own existence in his present.
Captured in a time corridor, the Doctor and his companions are forced to land on 20th century Earth, diverted by the Doctor's oldest enemy - the Daleks. It is here the true purpose of the time corridor becomes apparent: after ninety years of imprisonment, Davros, the ruthless creator of the Daleks, is to be liberated to assist in the resurrection of his army. Not even the Daleks foresee the poisonous threat of their creator. Indeed, who would suspect Davros of wanting to destroy his own Daleks - and why? Only the Doctor knows the truth. Will he descend to Davros' level of evil to stop him?
The Doctor and Leela must catch a killer on a vast mining ship run by robots and humans.
The cursed island of Fang Rock off the south coast of England is a place of rumour and tales of beasts from the sea. Three lighthouse men at the turn of the century face their fears when something comes from the sea to bring death to all it touches.
A man blinded in a childhood accident fights crime using his superhumanly-elevated remaining senses.
Exactly one year after young rock guitarist Eric Draven and his fiancée are brutally killed by a ruthless gang of criminals, Draven, watched over by a hypnotic crow, returns from the grave to exact revenge.
The Doctor, Jamie and Zoe arrive on an unnamed planet. At first believing themselves in the midst of World War I, they realise it to be one of many War Zones overseen by the War Lords, who have kidnapped large numbers of human soldiers to form the greatest army the universe has ever seen. At the helm of this plot is the War Chief, another renegade Time Lord like the Doctor. The creeping realisation sets in that the Doctor cannot solve this problem alone, and that his days of wandering may be at an end...
When the Master steals the Time Lords' secret file on the Doomsday Weapon, they grant the Doctor a temporary reprieve from his exile on Earth to deal with the crisis. He and Jo arrive on the planet Uxarieus and become enmeshed in a struggle between an agrarian colony and a powerful mining corporation.
On the eve of May Day, dark elemental forces begin to disturb the village of Devil's End as the Master summons the demon Azal: unexplained murders, a stone gargoyle come to life, and a nigh-impenetrable infernal energy dome. With the Master fully prepared to destroy the Earth, the Doctor and UNIT - aided by a benevolent practitioner of witchcraft - battle the wicked rites of a secret science wielded by an alien from another world.
Professor Emil Keller has created a machine that can pacify even the most dangerous of criminals. But when the Doctor and Jo arrive at Stangmoor Prison for a demonstration, things start to go horribly wrong - especially when they discover that the Doctor's old enemy the Master is responsible for the machine.