In Parasyte: The Grey, parasites from the sky fall onto Earth, take over hosts, and seek to control human civilization.
Choi Jun-kyung, the leader of Team Grey, says they don’t know where these parasites come from.
However, the opening of the series shows that they fall from the sky and hints that their arrival may likely have to do something with how humans are destroying their planet.
All of these parasites fell all at once in a larval state, appearing all over Korea and the world at large.
They synchronized with the bodies of human beings nearby. They can’t reproduce. Hence, there are not many of them.
Since humans quickly start understanding them, they don’t even get a chance to examine their existence, which is why the parasites follow their instincts. They devour human life and aim to survive.
Understanding the parasites
The parasitic organisms that humans are facing enter the human body through the ears, nose, and mouth and take total control of the host’s brain. They feed off the brain.
Once the parasitic organisms take over a human body, they can completely transform the heads of their hosts, controlling the rigidity and power of their cranial transformation and use it as a sharp blade to kill.
The smallest cells of these parasites can think like a human body. Once synchronized, the parasites run human brains completely.
The person’s consciousness is absorbed by the parasite. They are not humans any longer, and whoever the particular person was is gone. The parasites survive on human bodies and use them as a stable source of vital nutrients.
These parasites can’t survive on their own. They will shrivel up and die without a body. Hence, they are required to find another human body as quickly as they can once they leave one body.
The parasites are also quick learners. Throughout the first season, they come to understand human emotions such as love, trust, and betrayal and how humans operate.
Measures against the parasites
The Grey Special Forces Unit spends time researching and hunting down the parasites. To detect if a human being is carrying this parasite, Team Grey conducts an x-ray on all the police officers at Namil Police Station.
A test can also be done on a particular human being using a strand of their hair. Since the parasites are made up of a single cell mass, they can live briefly even if they are divided into pieces.
In the small sections, they lose intelligence as well as the ability to return to the main body.
To kill a parasite that is possessing a human body, one has to incapacitate the body. They can either bleed off the host’s body all at once or aim directly at the heart of the host’s body.
In this case, a knife or a shotgun will be more effective in killing these parasites. Lastly, the parasites can also detect other parasites that are in proximity to them using brain waves.
This is why Jun-kyung captures the parasite that has infested her husband’s body and uses it to track down other parasites.
This parasite, which Team Grey calls the Hunting Dog, assisted Team Grey in their research.
Team Grey has made the Hunting Dog wear a mask that is a clever device that dispenses a kind of chemical the parasites are susceptible to.
Jun-kyung holds a remote for this mask, which dispenses the chemicals, and the parasite will be immobilized.
The mask also comes with a sensor that monitors if the parasite transforms itself to escape. If that happens, the solution is promptly dispensed, bringing a great deal of pain to the parasite.