Know Your Cybermen No.6

Revenge of the Cybermen (1975).
The first appearance of the Cybermen in colour (save for a brief cameo in Carnival of Monsters). Some differences in design once more. The helmets are the same as those seen in their previous story, but the tubes are thicker, and ridged. The neck of the headpiece sits outside the costume, which is no longer based on a wetsuit. The piping around the body is also ticker and ridged, with quite chunky connections. Elbows and knees have reinforced bands around them. They have four fingers and a thumb on each hand (they only had two fingers and thumb per hand last time). Being the 1970's, they appear to have slightly flared legs.
We have the first appearance of the Cyber-Leader - denoted by having black markings on the helmet. This is the first time that the actors within the costumes have provided the voices. The leader often sounds quite emotional for a creature of cold logic. He is often to be seen posturing with his hands on his hips.
The Cybermen have guns built into their foreheads.
It is around the year 3000, and the Cybermen have lost a war. They now exist as a group of scavengers, without any home planet. They have an allergy to gold, and this metal was employed against them in the war when humans developed the Glitter Gun. Gold plates their breathing systems.
The planet of Voga had high concentrations of gold, and this was where the humans and their allies got their supplies from. The Cybermen destroyed the planet - but a large section, still inhabited, escaped. This has now entered the Solar System near Jupiter, and this group of Cybermen have come to destroy that. Whilst the story title mentions "revenge" - a human emotion - it is logical for the Cybermen to act in this way - to prevent Voga's gold being used against them again.
The Cybermen make use of a human agent to capture the navigation beacon in orbit around Voga, from which they will launch their attack. An artificial plague has been spread by Cybermats to wipe out most of the beacon's crew, but a small number of them will be spared. They will be forced to carry powerful bombs to the planet's core. These have sabotaged straps, to prevent their removal.
This plan fails when the relay device which boosts the bomb detonation signal is destroyed.
A back up plan involves loading the beacon with bombs, then crashing it into Voga.
This also fails when the Doctor diverts the beacon away from the planet, and a Vogan missile destroys the fleeing Cybership.

Story Notes:

• Producer Barry Letts had intended to bring the Cybermen back in Season 10. They would have featured in Frontier In Space, instead of the Ogrons. Terry Nation objected to having the Cybermen anywhere even remotely near his Daleks.
• Letts confirmed the Cybermen would be back soon in the Radio Times - possibly now for Season 11.
• With Tom Baker about to take over from Jon Pertwee, a story was finally commissioned from Gerry Davis to help establish the new Doctor, along with other returning foes such as the Sontarans and Daleks.
• Davis' initial idea was for the story to be set in a space casino, which is where the role of gold probably comes from.
• Script editor Robert Holmes rewrote the story heavily. He was never happy with it. Nor was producer Philip Hinchcliffe.
• The latter was also unhappy with the Vogan masks, which he thought lacked enough movement and expression.
• Several strange things occurred at the supposedly haunted caves in Wookey Hole where the location filming took place - after lighting crew had "mocked" a rock formation known as The Witch.
• This is the last appearance by the Cybermats in the classic series.
• This was the first story to be released on VHS, in a very expensive, edited form.