up counter measures to ensure the Cybermen will not be revived again. After resetting the defenses, he discovers the Controller is still functional and flees, working with the survivors to close it into the tombs. Whilst the others struggle to keep the Controller inside, Toberman sacrifices himself to close the doors, completing the circuit, and electrocuting both him and the Controller. With the rocket repaired, the expedition leaves, the Doctor and his companions bidding them goodbye. As they leave, they fail to spot a surviving Cybermat, which approaches Toberman's body. Production Writing Peter Bryant, who had previously been assistant to Gerry Davis and been newly promoted to script editor on the preceding story, was allowed to produce this serial in order to prove that he could take over from Innes Lloyd as producer later on in the season. Bryant's own assistant, Victor Pemberton, acted as script editor on this serial, but left the series after production of the serial was finished, deciding that he didn't want to be a script editor. When Bryant's eventual promotion to producer came, Derrick Sherwin became script editor. The working titles for this story were The Ice Tombs of Telos and The Cybermen Planet. Toberman was originally intended to be deaf, hence his lack of significant speech; his hearing aid would foreshadow his transformation into a Cyberman. Recording It was produced at the end of the fourth recording block but was deliberately held back to season 5, despite the fact a 'Next Week' caption was prepared for the final episode of The Evil of the Daleks, suggesting it was originally intended to end the fourth season. The exterior scenes for Telos were recorded at Gerrards Cross Sand and Gravel Quarry. The Cybermats were controlled by various means – by wires, by wind-up clockwork, by radio-control, and some by simply being shoved into the shot. When the team were not filming, it was known for the people controlling the radio-controlled Cybermats to chase Deborah Watling around on set. The scene of the Cybermen breaking out of their tombs was filmed entirely in one take. In the scene where the group are at the main entrance of the tomb, Patrick Troughton and Frazer Hines worked out in secret the brief sequence where both the Doctor and Jamie go to take Victoria by the hand and end up taking each others. They knew that, with the recording schedule