The Doctor's attempt to give Harry a trip in the TARDIS sees the two of them and Sarah Jane arriving onboard a space station in the far future, with some rather deadly security mechanisms.

The Doctor and Harry revive the Ark's medtech, Vira, to help Sarah Jane. But when station commander Noah is revived, he becomes suspicious of the newcomers.

Knowing that Noah has been infected by the Wirrn, the Doctor persuades Vira to halt the reviving of her people, knowing it will place them in danger as well.

The Doctor tries to protect the humans still in cryogenic suspension from the Wirrn, who are determined to use Earth as their new breeding ground.

The Doctor, Sarah Jane and Harry teleport to Earth to ensure the planet is safe for the survivors on board Nerva Beacon to return and reinhabit their world. A Sontaran named Styre has captured a group of humans and is conducting experiments on them to discover the human body's weaknesses, as part of the Sontaran's goal for domination of the galaxy.

The Doctor learns that Styre has been experimenting on the Galsec crewmembers to pave the way for a Sontaran invasion of Earth and decides the only way to halt his plans is to challenge him to a duel.

The orbit of Jupiter, the 25th century. Arriving back on the Nerva Beacon much earlier in history, the Doctor and his friends discover the satellite beset by space plague while its crew struggles to keep space traffic away from Voga, the newest moon of Jupiter. But what is the connection between Voga, the plague, and some old enemies of the Doctor?

The Doctor transmits Sarah Jane and Harry down to Voga to cure Sarah Jane of the Cybermat's poison but Kellman's sabotage means he is unable to bring them back.

The Cybermen force the Doctor, Stevenson and Lester to carry bombs to the centre of Voga while Sarah Jane, Harry and Tyrum decide to contact Vorus.

The Doctor, Harry and Lester try to destroy the Cybermen's relay device, while the Vogans prepare to destroy Nerva even though Sarah Jane is still on board.

The Doctor and Sarah answer a distress call and find themselves on Zeta Minor, the last planet of the known universe, where a Morestran expedition has gone missing.

The Doctor realises that Zeta Minor lies on the boundary between the universes of matter and anti-matter and something on the planet won't let the Morestrans leave.

The Doctor makes a deal with the Anti-Matter Beast to return all the anti-matter to the planet but Sorenson is determined to continue his research.

The Doctor tries to convince Sorenson to sacrifice himself for the rest of the crew but Salamar's attempt to deal with the situation causes their problems to multiply.

The Antarctic, the near future. A strange seed-pod is unearthed from 20-thousand-year-old ice. The Doctor and Sarah go to investigate, but are too late to prevent the pod infecting a scientist and unleashing a threat to all animal life on Earth...

Two employees of the millionaire Harrison Chase arrive at the Antarctic base, and they will stop at nothing to get hold of the second seed-pod.

The Doctor and Sarah Jane return to England after their Antarctic ordeal and Chase tries to eliminate them, but they escape and track him down at his estate, where he is preparing to open the Krynoid pod.

The Doctor is captured by Chase, who plans to breed the stolen Krynoid pod. He is placed in an automated compost hopper and only Sarah Jane can save him... but will she make it before the Krynoid grows to fruition ?

The Krynoid grows to a monstrous size and traps the Doctor and the others in a cottage. The creature demands they turn over the Doctor, while Chase seeks to make an alliance with the alien vegetation.

The Doctor, Sarah Jane, and Scorby are trapped in the manor as a possessed Chase stalks them from within, while the gigantic Krynoid prepares to crush them from without. Worse, the alien plant is ready to germinate, spreading its seeds across England.

Gallifrey, planet of the Time Lords. Summoned home by a premonition of murder, the Doctor discovers a dark conspiracy at the highest levels of Time Lord society... and his oldest enemy, who poses a threat to the existence of Gallifrey itself...

The President of the High Council has been killed and the Doctor is the prime suspect. The Time Lords are eager to dispense quick justice and the Doctor must race agains the clock to discover the truth... and an old enemy.

The Doctor has entered the computation Matrix to prove his innocence. But his opponent is prepared for him and the two engage in a mental duel to the death.

The Doctor has won his fight in the Matrix and revealed the assassin. But the Master is not defeated and sets a plan in motion that could destroy the Time Lords.

London, the 1890s. As magician Li H'Sen Chang captivates audiences, a spate of disappearances amongst young women goes largely unnoticed. But almost upon their arrival, the Doctor and Leela find themselves confronting the feared Tong of the Black Scorpion, and a menace from another time. And there's something fishy in the sewers, too...

The Doctor and Leela investigate the strange events in Victorian London. But a mysterious masked figure lurks in the shadows.

As Li H'Sen Chang works to secure the time cabinet, Leela pursues and investigates his master – the mysterious and murderous Weng-Chiang.

The Doctor and Leela attend Li H'Sen Chang's performance, hoping to confront the magician. But his master Weng-Chiang has other plans…

The Doctor and his allies try to track down Weng-Chiang before he can activate the time cabinet and possibly destroy London.

The Doctor and Weng-Chiang have their final confrontation in the mysterious House of the Dragon -- watched by the evil duplicitous Mr. Sin.