Science fiction and horror have blended well together like peanut butter and chocolate for a long time. One of the earliest examples is Mary Shelley’s classic literary work Frankenstein, or the Modern Prometheus and the melding continues to this day with assorted books, films, comic books, games and other media. Some of the standouts include the Alien films, I Am Legend, The Tommyknockers, the Predator films, Resident Evil, Event Horizon, The Fly, Dead Space, 28 Days Later, A Quiet Place, The Thing (and its source novel Who Goes There?), etc.
Why have the two genres been able to be combine so perfectly? That is to be debated since there are so many reasons and it may not be clear to many. But it can arguably be due for one factor and that is that the genre combo zeroes in to the fear of the unknown. Think about it, what makes horror so tantalizing is that it addresses what we’re afraid of, and that is ultimately death because it is the great unknown. What lies beyond death? Is it truly the end or the pathway to something truly horrific? Science fiction works have dealt with the nature of death and what it entails. As mentioned before, Frankenstein was all about defeating death and the horror of achieving this as Dr. Frankenstein found a way to bring the dead back to life through scientific means rather than using the supernatural.
Obviously it is the use of science or its grounded setting that sets science fiction horror separate from regular horror. And it is why it can be more unsettling…
With the regular horror genre, anyone experiencing it can take some small comfort with the idea in the back of the head that the horror story is implausible. There isn’t any way that a dead corpse will come back to life and start eating you, and despite all the so-called reality ghost hunting TV shows, the existence of spiritual entities still has not been scientifically proven. With films like The Thing, Alien or A Quiet Place, what makes them so terrifying is that we can encounter extra-terrestrial life that means us harm. Science experiments, research and discoveries that should benefit humanity can lead to disastrous results as seen in The Fly, Nightflyers, Event Horizon, Demon Seed, Blindsight, and The Strange Case of Doctor Jekyll and Mr. Hyde.
Then there is the sub-genre in science fiction and horror of humanity grappling with devastating diseases that falls into horror. Some like The Andromeda Strain are clear cut stories where diseases outright decimates us, but other works uses diseases to bring about body horror tales or create tenuously plausible zombie yarns. Examples include The Fireman, Black Hole, 28 Days Later, Cross, I Am Legend, and the Resident Evil franchise. Of course, saying that the events shown in these works are plausible is stretching things and as with any fictional work requires suspension of belief. But when the stories work and terrify us, they work quite well to the point that our rational brains stop questioning and start reacting to the horror of these stories.
Another thing to consider about how well the two genres blend so well is that the stories are often contemporary or take place in the future. These settings also lend to the feeling that what happens in them are possible. We don’t know that the first alien life we will encounter in the future will try to eat us or that using FTL will open a gateway to a hellish dimension. We cannot say for certain that these horrific events will happen.
What is even more unsettling is that what will actually occur in the future or just a few minutes from now can be far worse than what our puny minds can imagine. It all feeds into fear of the unknown and is why science fiction and horror are the perfect combination for storytelling.