On Skaro, Doctor Who and Romana (Lalla Ward) encounter their archenemies---the Daleks. Tyssan: Tim Barlow. Cmdr. Sharrel: Peter Straker. Agella: Suzanne Danielle. Lan: Toby Osoba. Veldan: David Yip.

The inhabitants of the planet Skonnos have been promised by an alien Nimon that he will restore their empire to greatness if they in return provide young sacrifices and radioactive hymetusite crystals, both of which they are obtaining from the nearby planet Aneth.

The TARDIS arrives on Fang Rock, a small island off the English coast, around the start of the 20th Century. The Doctor and Leela seek shelter at a lighthouse where the island's only inhabitants - Ben, Vince and Reuben - operate the recently-installed electric lamp to warn ships off the treacherous rocks.

The Captain seizes Romana, and it's the Doctor to the rescue. Romana: Mary Tamm. Dr. Who: Tom Baker. Mr. Fibuli: Andrew Robertson. Nurse: Rosalind Lloyd.

The final segment of the Key is traced to the planet Atrios, engaged in a long war with the Zeons.

The Doctor lands aboard a sandminer, whose crew are being murdered one by one.

The TARDIS is infiltrated by the Swarm - a space-borne intelligence that wishes to spread itself across the universe - and the Doctor is infected by its nucleus. The ship then materialises on Titan, one of the moons of Saturn, where the human occupants of a refuelling station have also been taken over.

The Doctor and Romana discover the war is being co ordinated by a computer called Mentalis.

The Doctor meets his match when he is summoned to Tigella, a planet whose energy source has become unstable. Tom Baker, Lalla Ward. Earthling: Christopher Owen. Zastor: Edward Underdown. Caris: Collette Gleeson. Brotodac: Frederick Treves.

Dr. Who battles a mind machine that contains an evil alien parasite. The Master: Roger Delgado.

An alien spaceship with a crew of statue-like humanoids lands on Earth.

The Doctor faces death when the Time Lords place him on trial for interfering in galactic affairs. Peri: Nicola Bryant. Melanie: Bonnie Langford. The Valeyard: Michael Jayston. Katryca: Joan Sims.

The Doctor and his companions encounter space lepers headed for a cure on "Terminus." Peter Davison. Kari: Liza Goddard. Olvir: Dominic Guard. Turlough: Mark Strickson. Nyssa: Sarah Sutton.

Amy and Rory are trapped on a crashing space liner, and the only way The Doctor can rescue them is to save the soul of a lonely old miser. But is Kazran Sardick, the richest man in Sardicktown, beyond redemption? And what is lurking in the fogs?

Part 1. The Doctor, Amy and Rory receive a secret summons that leads them to the Oval Office in 1969. Enlisting the help of a former FBI agent and the irrepressible River Song, the Doctor promises to assist the President.

Part 2. The Doctor is locked in the perfect prison. Amy, Rory and River Song are being hunted down by the FBI. But, with the help of President Nixon and Neil Armstrong, the Doctor is able to mount a rebellion against an alien invasion.

The TARDIS is marooned onboard a 17th-century pirate ship whose crew is being attacked by a mysterious and beautiful sea creature. Becalmed and beset by cabin fever, the pirates have numerous superstitious explanations for the Siren's appearance.

By following a Time Lord distress signal, the Doctor puts Amy, Rory and his beloved TARDIS in grave danger.

Part 1. A solar tsunami liberates doppelgangers from their human 'originals' in a futuristic factory. Can the Doctor prevent all out civil war?

Part 2. The Doctor must convince terrified factory-workers to work with their doppelgangers to overcome a monster of their own making.

The Doctor assembles an army to face the Battle of Demons Run - and River Song has something to tell him.

The TARDIS crash lands in 1930's Berlin, bringing the Doctor face to face with the greatest war criminal in the Universe. And Hitler.

Every child is scared of monsters, but George's terrified pleas for help reach the Doctor. Because George's monsters are real.

In Wales, items include a "Dr. Who" script and pottery.

Amy is trapped in a quarantine facility for victims of an alien plague. Can Rory save her before she is killed by kindness?

The TARDIS lands in a hotel where every visitor's room contains their deepest, darkest fears. What lies in wait in the Doctor's room?