The TARDIS lands in a petrified forest on an alien planet. Determined to explore, the Doctor leads his companions into the metal city, where they discover the danger of what will become his deadliest enemies, the mutant Daleks. (Originally broadcast in seven parts.)
Ian, Barbara and the surviving members of their party try to find a way into the Dalek City whilst Alydon prepares the other Thals for an attack. But only the Doctor and Susan are aware of the full extent of the threat the Daleks pose.
In this completely TARDIS-based story, the crew find themselves and their ship acting very strangely indeed. Blame runs high for the Ship's unusual behavior, until the Doctor realizes the TARDIS itself may be trying to warn them... (Originally broadcast in two parts; also known in fan circles as "Inside the Spaceship.")
The TARDIS arrives on Earth in the 13th century, where it is claimed by famed explorer Marco Polo as a gift for his employer, Kublai Khan. Polo hopes to finally buy his way out of the Khan's service - but if he succeeds, the Doctor and his friends will never be able to get back to their Ship ever again... (Originally broadcast in seven parts.)
The Doctor and Susan are able to supply Marco with condensation that has formed inside the TARDIS, saving the group from dying of thirst.When the group are reunited with Tegana, the travelers begin to suspect he is up to something.
On the planet Marinus, the Doctor and his companions are enlisted by Arbitan to seek out the keys to an ancient and powerful machine. Their quest takes them across time and space; will they be able to return the keys before Marinus falls under the control of the alien Voord? (Originally broadcast in six parts.)
The TARDIS arrives on Earth landing in 16th century Aztec society. Barbara goes off exploring - despite the Doctor's orders not to wander off - and is taken away by the high priest Autloc who believes she is the reincarnation of the goddess Yetaxa. They believe it is a sign that the rains - which are late - will now come. The high priest of sacrifice Tlotoxl recruits Ian to lead their army but he finds he has a rival in Ixta. Ian is less than comfortable with his role when he learns that they are to deliver the human sacrifice to the high priest at the rain ceremony. ...
The TARDIS arrives aboard a spaceship that has been captured by the Sensorites, a hearing-sensitive alien race. The Sensorites are dying, and the Doctor finds himself forced to investigate the origin of the mysterious illness. (Originally broadcast in six parts.)
The TARDIS lands during the French Revolution, where Ian, Barbara, and Susan become caught up in the politics of the day. When they are arrested and set to be executed, the Doctor must take on the disguise of a public official to try and save their lives. (Originally broadcast in six parts.)