Science fiction and horror are natural allies. Science fiction can liberate an author's creativity to come up with new stories and this suits the horror writers’ ability to create imitative ways to scare the reader. Nowhere is the more true than in film, where sci-if concepts can be used to as to unsettle, creep out or completely terrify the audience.

Below is a selection of my five favourite sci-fi horror movies. Before we get started I want to issue a brief spoiler warning for the films that will be discussed below.

The Fly

The sci-fi concept of teleportation serves as the basis for this horror movie. Jeff Goldblum starts as eccentric scientist Seth Brundle who is secretly working on a teleportation device. After some initial failures Brundle gets the device to work with the help of journalist Veronica Quaife (Geena Davis). However when Brundle test the machine on himself he is impaired by jealousy, anger and alcohol and does not notice a common household fly has entered the device. Brundle is fused into a hybrid half-man half-fly creature and over the course the film looses his humanity.

The Fly uses our fear of our animal nature to increase tension. As Brundle becomes more fly he begins to operate under the primal drives of rage and sexual desire. The control that a human usually has over these desires are stripped away as Brundle embraces his animal side. When Quaife discovers that she is pregnant and dreams about giving birth to giant maggot, the film takes darker turn. Brundle is concerned that the child is the last remnant of his humanity and kidnaps Quaife to force her to have the child.

The Fly plays off our fear of break of the thin layer of humanity that separates us from animals. As Brundle becomes more fly he stops suppressing his basic animal desires and becomes more dangerous. In the Fly, the real monster is not the thing Brundle is coming but it is the animal within himself that has been set free.

The Mist

Cinematic adaptations of Stephen King stories have a mixed tracked record for every Shawshank or the Shining there is a Maximum Overdrive or the awful TV adaption of the Stand. However the Mist delivers as a horror movie, it is tense, claustrophobic and violent.

The Mist stars Thomas Jane who wakes up after a thunderstorm to discover a tree has fallen on his house. He takes his son and neighbour to a grocery store where a strange mist surrounds them. Whenever anyone ventures out into the mist strange creatures devour them.

The tension in The Mist comes from setting, the characters are besieged inside the shop and any escape attempt will result in certain death. Events escalate as a Christian woman forms a doomsday cult around here and inevitably some the monsters break in. The Mist keeps the suspense up by showing as little of the creatures as possible, cloaking them in the eponymous mist, but frequently reminding the audience of how much danger the characters are in.

The sense of hopelessness and impending death makes The Mist both dark as well as tense and bloody. Like most of the best horror films the worst events in The Mist are caused by humans and not the creatures that have them trapped.

The Thing

Low budget and with plenty of gore, is a winning formula for horror movies and John Carpenter is the master of this approach. Without a doubt his best film is the Thing for being both suspenseful and gory. An alien space ship crashes near an Antarctica research station and the survivor is not friendly. After killing several of the humans, the base’s inhabitants try to fight back. There is only one catch; the Thing that is praying on them can disguise itself as any of the humans.

The fear of the enemy within your ranks runs across all of humanity and the audience can engage with the sense of paranoia that grips the characters. Unlike most horror movies, the Thing is not an external enemy killed but an internal enemy that must be rooted out. As the Thing spreads and takes over more of the humans we see its true form, a disgusting mix of organs, tentacles and bodily fluid. The Thing moves between tense physiological thriller and out and out gore-fest frighteningly quickly.

A sense of isolation runs through the entire film, which adds to the tension. In Antarctica no one will come to the characters rescue so they must deal with the Thing themselves, before it makes its way to the rest of civilisation and dooms humanity.

The Thing has enough physiological tension to be interesting and enough gore to be exciting. The use of the enemy within story works with the low budget approach and means that when we do see the Thing, it is brief enough and detailed enough to be truly shocking. The Thing is a low budget gore film with an added physiological element that makes it enduringly scary.

Event Horizon

A trip to the edge of the solar system to test a new piece of wormhole technology, what could go wrong? Expect the wormhole created goes to hell and the ship becomes possessed by a violent and malevolent force. The premise of Event Horizon may sound daft but the execution is frightening.

Event Horizon works so well because the revelation of what has happened is spread out over the course of the film. Event Horizon starts with a straightforward rescue mission, which slowly gets worse and worse. Sam Neill is great in the role of the wormhole ship’s creator who goes slowly insane when he is confronted by what he has created.

The tension builds through theological horror, confined spaces, no escape in space, and through moments of gut churning gore. Director Paul W.S. Anderson makes able use of both approaches to horror.

Event Horizon starts off as science fiction and becomes fantasy as the plot develops. As the story moves away from our reality so does the tension until the audience is lost in a world of pain and chaos. When the final revaluation comes it makes perfect sense in the context of the story and is completely terrifying.

Alien

One of my favourite movies of all time and certainly my favourite sci-fi horror movie. Ridley Scott's atmospheric horror movies owes as much to the art of H.R. Giger and Francis Bacon as it does to the science fiction of Isaac Asimov. The tension builds slowly and steadily, there is little music and it is long time before the mysterious predator is revealed. When it is finally shown to us it is the stuff of nightmares, a creature that is completely alien, impossible to reason with and utterly deadly.

When the freighter Nostromo picks up a strange signal they divert to investigate an uncharted planet. When the crew lands, they discover a crashed alien spaceship and a huge horde of eggs. One thing leads to another, John Hurt sticks his face in an open egg and later an alien killing machine explodes out of his chest and starts picking off the crew. It’s left to Ellen Ripley (Sigourney Weaver) to escape the before she too is killed.

The production design of alien lays on the atmosphere, the Nostromo is all steam pipes, cramped spaces and dark places to hide. I cannot think of anywhere worse to be trapped with a monster. The tension builds as the body count rises and leads to a terrifying final confrontation between Ripley and the alien.

Those are my favourite sci-fi horror movies. Do you have any to add to the list? Let me know below.