The Cybermen's Logo

The TARDIS arrives on the planet Telos and The Doctor, Jamie McCrimmon and Victoria Waterfield discover that an archaeological team, led by Professor Parry, have uncovered the doors to a lost Cyberman city.

After a member of the archaeological team is electrocuted, when he tries to open the huge doors, and then with the help of Toberman, Kaftan's aide, who is strong enough to pull the huge doors apart, they all enter the chamber beyond and start to explore. They discover in the main chamber a sealed hatchway, apparently leading down, and two rooms. One which they deduce must have been used to revitalise dormant Cybermen, while the other, which contains a large screen, at first is a mystery. They also discover a strange small metallic mouse-like creature that appears to be dead.

Meanwhile the expedition's patron, Eric Klieg, and Professor Parry, in the main chamber, puzzle over the mathematics behind operating the power systems. The Doctor gives Klieg the solution but despite warning him not to activate the machinery Klieg takes no notice allowing power to hum through the complex.

Inside the TARDIS

In the revitalising room Victoria, finds herself trapped inside a large Cyberman-shaped sarcophagus when the power comes on. She is eventually freed by The Doctor before any harm is done. However, in the other room, Jamie does not realise that he is in a weapon testing facility which, now the power has been restored, has become active and, when a dummy Cyberman appears in front of them, a weapon hidden in the wall fires hitting a member of the archaeological team. The Doctor rushes into the room but is too late to prevent the accident. Meanwhile Victoria, who has followed The Doctor, discovers the inert silver creature, which The Doctor identifies as a Cybermat. As it seems harmless she picks it up off the floor and puts it in her bag.

Back in the main chamber Parry and Klieg carry on using the equations The Doctor gave them in an attempt to discover how to open the hatch. They are successful so allowing the archaeologists to explore below. There they discover the frozen tombs of the Cybermen. As they start to explore they are shocked to hear the hatch above them slam shut. Klieg though seems unconcerned as he plans to open it from a control panel that has been discovered in the tombs. But instead the switches he uses start to defrost the tombs and the Cybermen within begin to stir.

Defrosting Tombs

Meanwhile up in the main chamber Victoria and Kaftan, who had stayed behind while the others went below, find themselves both in danger. Victoria, who had fallen in a drug induced sleep, wakes to find Klieg pointing a gun at her. At first neither of them spot the Cybermat, that was in Victoria’s bag, slowly come to life and scuttle across the floor. Suddenly, it heads straight for Kaftan and jumps up at her. Shocked by this sudden attack Kaftan drops the gun which Victoria manages to grab and then fire at the creature – killing it. With Kaftan unconscious Victoria tries unsuccessfully to open the hatch. Having no joy she decides to go to the archaeological team’s spaceship to seek help.

Back in the tombs Klieg explains that he is a member of the Brotherhood of Logicians, a group who seek to rule Earth by the rules of logic. He has come to Telos to discover the Cybermen's secrets to help the Brotherhood. While he is explaining this the Cybermen emerge from their tombs and release their Controller. The Cybercontroller tells the humans that they now belong to the Cybermen and will become like them. He reveals that the tombs are an elaborate trap to bring highly intelligent humanoids to Telos to be converted into Cybermen and thus re-build the Cyber race.

Suddenly the hatch above is opened (thanks to Captain Hopper, from the archaeologist’s spaceship, who Victoria managed to seek help from). Captain Hopper descends armed with some smoke bombs. These he sets off confusing the Cybermen and allowing everyone except Klieg and Toberman to escape. Toberman finds himself trapped and is taken away to be converted while Klieg manages to escape via another route to the surface. He finds Kaftan in the weapons testing room and between them they remove the laser gun from the dummy Cyberman and plot to use it to seize control.

Kaftan

Below the Cybercontroller orders the preparation and release of more Cybermats, which are sent through pipes into the chambers above the tombs to attack the archaeologists. The Doctor though is able to fend them off by using an electrified cable to create a magnetic field that disorientates and destroys the creatures. It is then that Klieg enters the main chamber brandishing the laser. He believes that with his new weapon he can negotiate with the Cybermen. Kaftan opens the hatch and Klieg calls for the Cybercontroller – who climbs up, accompanied by a partially converted Toberman who is under the Cybermen’s control.

However, the Cybercontroller’s energy is running low and with most of the Cybermen back in their tombs to conserve power, Klieg uses this to demand the release of Toberman and the Cybermen's help with the conquest of Earth. The Cybercontroller agrees as long as they help him be revitalised. In the revitalising room The Doctor helps the Cybercontroller into the sarcophagus in an attempt to trap it there. But the Cybercontroller still proves to be too strong and manages to break free. In the struggle Kaftan is killed by the Cybercontroller when he picks up the cybergun Kleig has dropped in the confusion.

The death of Kaftan and the urging of The Doctor shakes Toberman out of his controlled state. He struggles with the Cybercontroller and hurls it into a control panel, apparently killing it. The Doctor takes Toberman with him back down into the tombs so that they can re-freeze the remaining Cybermen. However, Klieg follows them down and starts the sequence to re-awaken the Cybermen but suddenly he is attacked by a Cyberman and killed. Toberman grapples with the Cyberman and manages to destroy it so allowing The Doctor to successfully re-freeze the tombs.

The Doctor, when everyone is out, re-electrifies the city doors but the Cybercontroller recovers and tries to prevent the doors from closing. With the help of Toberman, who is stronger, the doors finally shut. But as soon as both doors make contact with each other a powerful electric pulse kills Toberman and apparently the Cybercontroller. With the tombs sealed, and the remaining members of the archaeological team safely aboard their ship, The Doctor and his two companions head back to the TARDIS. No one though notices a lone Cybermat, moving along the ground outside the doors to the city toward Toberman's body.