Welcome to Horrorhead, a fortnightly column about the dark, twisted part of science fiction - the part that borders on horror. If you're looking forward to I Am Legend next week, you know it's basically a vampire horror story translated into a microbial scifi nightmare. But what makes I Am Legend scary isn't the spectre of virus-deformed post-humans. It's something more fundamental.

The true horror in I Am Legend, and other stories like it, is having to watch what happens to people when they're robbed of society. It's no accident that Mary Shelley, author of horror-scifi classic Frankenstein, later wrote a post-apocalyptic book called The Last Man. Like many storytellers in the genre, she knew that no monster is scarier than a human being without companions.

Often the aloneness monster rears its head in post-apocalyptic scifi: New Zealand indie Quiet Earth tortures us with fear when our protagonist discovers he's the last guy on the planet; and the masterful 28 Days Later amps up the fear right away when the hero awakens to find himself alone in the middle of an abandoned London. Possibly the most desolate portrait of this aloneness comes in Vernor Vinge's novel Marooned in Realtime, where a handful characters who can travel forward in time find that they've "jumped" to a future where humans are mysteriously gone. The time-travelers head to the future in longer and longer jumps, trying to reach a world where apes or spiders have evolved into intelligent life that can keep them company. But it doesn't happen. The sun just grows older and dimmer, and the lost humans never cure their species-loneliness.


Of course, there's being completely alone and then there's being "the only one." Being completely alone can sometimes be peaceful, as Ripley demonstrates in Alien when she crawls into her pod after ejecting the alien into space. But being the only human left in a world of mutants, super-evolved apes, or alien invaders - that's more typical in scifi horror. It forms the basis of often-retold stories like Invasion of the Body Snatchers and countless Alien ripoffs (often little more than slasher movies in space).

Still, no matter what horrifying creature menaces that army of one, the true terror lurking beneath the surface is the loss of protective community. This isn't a fear that humans reserve for themselves, by they way. The scary parts of E.T. (and yes, there are some) have to do with E.T. being a castaway who is vulnerable on a world dominated by homo sapiens. And those who read Frankenstein know that what makes the reanimated man into a monster is his realization that he's alone among creatures who want him destroyed.

Image from Marooned in Realtime book cover by Stephen Martiniere.