Parallel Earth (Telepresence)
Talk about it here.
After devastating the planet, the Cybermen captured this Earth’s human population and held them captive within numerous underground caverns across the world. Each cavern was filled with thousands of pods that harvested the bioelectrical energy generated by the humans and transmitted it to the billions of Cybermen connected to the Cyber-Mainframe across the multiverse. With the planet conquered and reduced to a desert-like environment, littered with the remains of buildings resembling those of 21st century N-Space Earth, the Cybermen installed the Machine to monitor the planet’s security before commencing full seeding of the wider universe. (AUDIO: Telepresence, Code Silver)
Sometime later, Petronella Osgood, Colonel Shindi and Josh Carter of the UNIT of N-Space travelled to this parallel Earth in the form of dimension bridge avatars, during an experiment with some virtual-reality headsets acquired from the Auctioneers (which were later revealed to be dimension bridge technology). After evading numerous mutated wild dogs the Machine detected them and attempted to convert them, attacking with a gigantic Mechanising Worm. The three UNIT personnel escaped over some old rooftops, only to be pursued by a dog that the Mechanising Worm converted. After destroying the converted dog and using the capabilities of the dimension bridge technology to escape from the Mechanising Worm, they discovered this Earth’s Piccadilly Circus and escaped from a swarm of converted pigeons into a huge underground network of train tunnels.
The group eventually found one of the Cybermen’s human battery caverns, containing thousands of pods, each filled with a person that once lived in Piccadilly Circus. The Machine then confronted Osgood, Shindi and Josh before attacking them with Mechanising Worms, their mental avatars being used to complete the link to N-Space that the Machine had already begun to establish within Sam Bishop, (AUDIO: Telepresence) who had previously been forced to use the dimension bridge technology by the Auctioneers. (AUDIO: Game Theory) Osgood, Shindi and Sam were virtually converted and a dimension bridge formed in the laboratory of the UNIT base Fortress Island, where the experiment had occurred. The Machine then activated Hive Section 49, converting ten of the humans in the pods into Cybermen to begin the invasion of the Earth of N-Space. (AUDIO: Telepresence)
Shortly before Kate Stewart detonated a nuclear warhead on Fortress Island to stop the Cybermen from breaking out of the fort, (AUDIO: Code Silver) the Master arrived in his TARDIS from this parallel Earth, having salvaged various pieces of technology from the planet to repair his damaged TARDIS after its crash-landing. When the dimension bridge to the Earth of N-Space was formed, he used the opportunity to fly his TARDIS back into his home dimension. After the Cyberman invasion was stopped by the Master, the dimension bridge shut down, closing the connection between the two Earths. (AUDIO: Master of Worlds)