I find it interesting how the Cybermen in the The Tenth Planet and The Moonbase are so different, but also the latter seems like a natural evolution of the former?
The Cybermen in The Tenth Planet arrive on Earth and announce their intentions and their history. Their planet Mondas, twinned to the Earth and her people, went out into the depths of space, and out there in the cold depths of the void they had to change. Rebuild themselves. Survive. But Mondas is sick and dying, and only one of these twinned planets can survive. The only way to save it is for it to feed on the energy of the Earth, destroying it.
The Cybermen here are twisted, but ultimately human. They cover the remains of their skulls with soft, sterile surgical cloth and leave their last piece of unaltered biology, their hands, exposed. Its like a horrific attempt to make people emphasize with them and their need to survive. To show they're still people. Their voices are all twisted sing-song tones and calm explanations of their intentions. They plan to let Mondas feed on the energy of Earth, and to convert all of humanity to Cybermen, forcibly if need be, to save them. Then Mondas will return to the void, with humanity now living on as empty shells, but survivors in the depths. To them this is a diplomatic answer to the problem.
Ultimately, however, this doesn’t work out. They are rejected, their plans fail. Mondas's feeding on the Earth ironically causes its own destruction and as they bonded themselves to her, the Cybermen die with her.
But some survived. The Moonbase shows that some Cybermen survived the destruction of Mondas. They don’t announce their intentions any more, they work in secret. They use an engineered virus to pick off the members of the Moonbase's crew, and intend to use its gravity controlling weather device to simply wipe the planet Earth clean of all life. Humans are too dangerous to leave alive, and are slowly making their way into the stars. To the Cybermen this isnt revenge, simply a task for self-preservation.
Instead of a soft cloth-bound face that attempts to reassure the onlooker of their organic origin, their skulls are clad in sleek, cold metal. They leave no skin exposed now, and in place of the sing-song tones of the diplomat now crackles a crude, almost indecipherable robotic monotone. The Cybermen no longer need to show their humanity, their reasoning. They no longer need to be diplomatic. All they're focused on now is efficiency, working from the shadows with a cold dispassion to end life on Earth for their own survival. One twisted offer of brotherhood was all they were going to give us.
I like how as well as being a 'redo' of the Cybermen concept and design, their appearance in The Moonbase works without throwing the original away. The group of Cybermen in The Moonbase seem like a natural evolution for the Cybermen to take after the events of The Tenth Planet, and the appearance and actions the Cybermen of The Tenth Planet seem like a natural first attempt at contact with humanity.
And I feel like the two stories being structured so similarly actually works in their favor. By putting the Cybermen in a similar plot and setting, it emphasizes how their approach and methods are different now. It would be one thing to just run the same plot again, but The Moonbase feels like a natural next chapter to The Tenth Planet, and I feel its a really good follow up.
