The Doctor, Jamie and Victoria arrive on Telos, where an archaeological group are exploring the Tomb of the Cybermen. But are the Cybermen as dormant as they believe?

The archaeologists learn they are stranded on Telos and Klieg suggests they use the opportunity to explore the Cybermen's tombs.

The Cybermen have been revived and plan to convert the archeologists into their own kind, prompting Hopper to attempt a rescue.

Klieg attempts to do a deal with the Cybercontroller while the Doctor tries to find a way to refreeze the Cybermen permanently.

When the TARDIS materialises in the Himalayas, the Doctor decides to pay a return visit to the nearby Det-Sen monastery only to be accused of murder.

Jamie and Victoria make their way to the monastery shortly before it is attacked by the Yeti.

While the Doctor and Jamie return to the TARDIS for equipment, the control sphere Jamie brought to the monastery is reactivated.

The Yeti escapes from the monastery and Victoria and Thonmi are accused of assisting it, while the Doctor and Jamie endure a perilous journey back across the mountains.

Victoria falls under the mental influence of Padmasambhva as the Yeti attack in order to drive the monks from the area.

With the Great Intelligence on the verge of becoming corporeal, the Doctor challenges Padmasambhva to a mental battle in order to defeat it.

The Doctor, Jamie and Victoria are brought to a base which is attempting to halt the flow of the Second Ice Age.

Varga revives and takes Victoria hostage as he works to revive his crew while the Doctor and Jamie find Penley stealing medical supplies.

Jamie and Arden venture out to rescue Victoria only to find the rest of the Ice Warriors are now active.

The Doctor leaves the base to try and find Jamie and Victoria while Storr tries to do a deal with the Ice Warriors.

The Doctor and Victoria are both held prisoner by the Ice Warriors as Varga decides to take over Brittanicus.

The Doctor and Victoria attempt to force the Ice Warriors to surrender control of the ioniser before the ice flow destroys them.

After the Doctor is attacked by a group of mysterious gunmen, he discovers he is the physical double of the famous scientist Salamander.

Jamie and Victoria agree to accompany Astrid to Hungary to observe Salamander's activities.

Jamie and Victoria join Astrid into attempting to rescue Denes but Salamander becomes suspicious of them.

Fariah brings the Doctor and Kent evidence of Salamander's activities but then they come under attack from Benik.

The Doctor persuades Bruce to help him infiltrate Salamander's research centre while Salamander takes drastic action to prevent Swann finding out the truth.

The Doctor discovers the true link between Salamander and Kent while Astrid tries to convince the shelter inhabitants they have been lied to.

The TARDIS becomes trapped in space before ending up in an underground station of a mysteriously deserted London.

Jamie and Victoria are reunited with Travers before Jamie joins the soldiers in attempting to find out what has happened to the Doctor.

The Doctor and Victoria are taken back to the Goodge Street base by Colonel Lethbridge-Stewart where the Doctor becomes convinced there is a traitor in their midst.