The Nestene Consciousness is a collective telepathic intelligence that has been colonizing planets for a thousand million years. In order to do this, it divides itself up into a number of translucent polyhedrons, each 8.5 inches in diameter with a volume of 3,000 cubic centimeters inside. These "energy units" (some pink, some blue; they may fade to blue after being exposed to a planetary atmosphere for some length of time) move through space in formation, and when they reach their target planet, they come down to the surface through a thin funnel of superheated air about twenty miles in diameter. This is first done with a spearhead of five or six "meteorites" (apparently using warp shunt technology to infiltrate the civilizations); once these have become established on the planet, after about a six-month period, another fifty or so land in the same area. This seems to cause a heat wave in the area.
The Nestenes have a natural affinity for plastic; they are able to energize it and turn it into quasi-organic matter, almost as though they are possessing it. Anything made of plastic can come under their control. The Nestenes use as their servants the Autons - plastic mannequins which they construct themselves. It is unknown how the Consciousness spearhead is able to fashion the first Autons, but their considerable mental powers may allow them to create Autons through willpower alone.
Once the Nestenes have some Auton servants, they take over a plastics factory, convert it to automation and fire most of the workers, to allow them to mass-produce Autons in relative secrecy. When the main group of Nestene energy units lands on the planet, the Autons are sent to collect them. As the energy units emit a signal, and glow in time to it, the Autons are able to trace them easily unless the signal has been muffled somehow. If this happens, usually the energy units can increase their pulsation signals. One of these energy units is the Swarm Leader, who of course is vital to the operation; despite this title, the Nestenes do not have an individual identity.
As the energy units are collected, the parts of the Consciousness are transferred to an environment tank. With one of these, the energy units can create the perfect lifeform for operating on the current planet. On Earth, their chosen shell was much like an octopus, with many large, suckered tentacles, some of which tapered to a point and others of which resembled squid tentacles. A future invasion attempt utilized a form made of living plastic, looking rather like a pool with a giant face, which could talk.
The Nestenes' telepathic powers enable them to control the minds of those working for them. They also promise not to destroy those who help them, which of course is a great big lie. These powers also enable the Nestenes to detect brain prints, so that the Autons can track down anyone that they want killed. In fact, the Autons themselves are also controlled telepathically, via a signal that is amplified by a large radial transmitter.
The Autons ordinarily look like blank-faced mannequins. They are apparently made of solid plastic, animated by the Nestene Consciousness. (Some, however, appear to exude green liquid when destroyed.) Their right hands are hinged in front of the thumb, and the front part can drop away to reveal a cavity inside, from which extends a nozzle. This weapon fires over very long distances, and it is quite fatal. Should the Auton's master wish to leave behind no trace, they can request "total destruction", in which the body ignites, then seems to implode, leaving behind absolutely nothing. Generally, the Autons are indestructible - they are not harmed by bullets, they get right back up after taking long falls, and nothing else seems to hurt them. The only way to destroy them is to first destroy or repel the Nestene creature, after which all the Autons collapse. (The Nestene Consciousness believes that it, too, is indestructible, probably because of its strong mental powers, indestructible servants and noncorporeal form; however, its living-plastic form can be destroyed with anti-plastic.) If the signal is completely cut off, the Auton may even melt. Autons are very swift runners, and also very strong, being able even to punch through metal doors. Initially they do not speak, but make a loud buzzing noise. However, later Autons do not buzz and possess an electronic voice (which may be the Nestene Consciousness speaking through them).
Autons are useful for covert purposes, as well, for they are easily disguised. Some have gone "undercover" as shop-window dummies, which activated all at once, broke out of their windows and began massacring people in the streets. They have also masqueraded as policemen and daffodil sellers wearing carnival masks. The Nestene Consciousness can also copy people to create precise Auton replicas, although the originals must be kept alive to maintain the copy. Autons have the power to change all or part of their form instantaneously; for example, metamorphosing their hands into blunt wedge-shaped clubs.
The Nestenes also utilized other methods of plastic death during their time on Earth. They created a black chair made of cold, clammy plastic that could suffocate the person that sat in it. They manufactured a solid-plastic troll doll, activated by heat, that strangled its victims. They distributed 450,000 plastic daffodils that, when exposed to shortwave radio signals, would seek out the nearest target and forcefully eject a plastic film to cover the victim's nose and mouth, suffocating them within ten minutes. They also used a long plastic phone flex, activated by a certain frequency of sound, which would wrap itself around its victim, either to suffocate or squeeze them to death. Wheelie bins acted like flypaper, affixing a victim's hand to the surface and then trapping him inside, to be taken for copying.
During the first Nestene invasion, the Consciousness created facsimiles of important government figures, perfect down to their brain cells and memory traces. These were kept temporarily in Madame Tussaud's wax museum until needed, when they were to replace their real-life counterparts. The Doctor managed to develop a device that emitted a sound frequency which disrupted the Autons and destroyed the Nestene. When the Auton facsimiles collapsed, their features reverted to normal and the real-life people they were based upon awoke.
On their second attempt, they were aided by the Master, who helped them to establish their new plastics factory. They planned to set off all the plastic daffodils simultaneously with a radio signal, and in all the confusion land their invasion force, using a radio telescope as the bridgehead. When the Doctor pointed out to the Master that the Nestenes would not distinguish between him and the humans, the Master had a change of heart and helped to send them back into space.
The Nestene Consciousness attempted to invade Earth again after their the Time War caused their protein planets to rot, destroying their food stock. As the smoke, oil, toxins and dioxins in Earth's air made it perfect for the Consciousness' needs, it attempted again to overthrow and destroy the human race. However, the Doctor quickly put an end to it with a vial of anti-plastic.
