10 scariest plagues from sci-fi and fantasy

Photo: The Expanse: Season 4.. Image Courtesy Amazon Studios

7. The Protomolecule from The Expanse

Who says all plagues have to happen on Earth? Science fiction has some truly terrifying pathogens and parasites that exact a heavy price on humans for their curiosity about the cosmos.

Few are as deadly or disconcerting as the Protomolecule from The Expanse. It’s alien in origin, of course, as most good sci-fi plagues are. It feeds off radioactivity and can totally obliterate a human if they come into contact with even the tiniest droplet of it.

I say “obliterate” because the Protomolecule does more than just kill a person or turn them into a zombie. First, it swiftly takes hold of their anatomy, turning them into what the novels lovingly call “vomit zombies,” people who are infected but have yet to keel over and instead run around infecting other people. During this period, bursts of blue light crack through their skin and eyes and generally mutate their body. After the human hosts die, they typically decompose into the greater collective consciousness of the alien virus.

Yes, you read that right. The sentience of the Protomolecule is something that humans have to contend with and constantly learn more about, as it is very clear right from the beginning that this thing infects with a purpose.

What that purpose is is a mystery until a decent way into the series, so for the sake of spoilers we won’t discuss it here. But suffice it to say that when the Protomolecule is set loose on an unsuspecting space station, it quickly wipes out the populace and turns the entire asteroid the station is set on into one giant, pulsing blue ball of alien terror. Not something you want to mess around with.