Lytton and Griffiths are wandering across a quarry. It actually is a quarry. Something is being dug up or mined there, by slaves watched over by Cybermen.
Lytton has a device that detects Cybermen.
"There are two very close," he says.
"That's right!" shouts a very human voice from behind him.
Bates and Stratton - two escapees from the Cybermen's labour gangs - disarm and frisk Lytton and Griffiths.
Lytton has been looking for them, and they've been looking for him.
"Are they Cybermen?" asks the perplexed Griffiths.
"Almost," says Lytton, amused.
"This is what the Cybermen do to you..." sneers Bates, removing his glove and sleeve to reveal a cybernetic arm, a chilly construct of steel and pulleys. His metal hand closes on Griffiths' fleshy one and squeezes. Bates watched Griffiths' pain with dead eyes.
"How much of you?"
"Arms and legs."
Bates and Stratton are rejects from the Cyber-conversion process. The Cybermen turn their rejects - the ones that cannot be entirely consumed - into labourers in their quarry.
So... the Cybermen start with the arms and legs. The legs that give locomotion. The arms and hands that lift and move and dig and manipulate. The organs of physical work.
When the Cybermen catch Lytton and subject him to conversion, they start with his arms.
The original Cybermen had human hands.
The severed hand is a recurring motif of the gothic.
The gothic is about dead labour, the living death of alienated work, the physical invasion and evisceration wrought by capital upon the working body, and the occult process whereby wealth is created from labour.
The Cybermen - with their skull-faces - are gothic things. Zombies, in the old fashioned sense. People reduced to pure labour power.