Alien Sex, it transpires, in the introduction to this anthology, was not the title Ellen Datlow wanted. She favoured something more subtle, this one just grew on people. But it suits the collection well: a hard, blunt, primal composite. Alien, which means nasty. Sex, which means poking a fraction of your delicate and precious self (doesn't have to be a penis: a finger, maybe?) into something icky. Into the alien out there. Which may or may not be alive but which is definitely hostile. It has to be, since it isn't part of precious you.

Datlow's organically grown title is a clear warning. Any fool who picks this book up expecting mild porn with tentacles deserves the sad disappointment they're going to get. Most of the stories are decidedly downbeat: more to the point they are extremely, self-consciously serious. The term ‘consciously’ is important here. Sex, per se, is one of those characters one should refuse to work with, on the children and animals rule. The subject will almost certainly upstage the writer. Fucking is so personal. We all have our funny little ways. The risk of being inadvertantly hilarious is so great that the only sensible approach is to be awfully, awfully serious; or to pass the whole thing off as a joke. But even jokes aren't safe, because fucking is so political. The who-does-what-to-whom of it can so speedily wipe the smile off your reader's face, turning a harmless bit of fun into a sickening satirical fable. William Gibson, in his foreword, suggests that this is a post-AIDS, post-feminist book. But there's more to it than that. Ghastly and death-dealing venereal disease isn't new (what about syphilis?). Nor is the battle of the sexes. What Alien Sex describes is the state of sexual play in a world that has become highly sensitised—by a whole complex of historical, scientific, sociological effects—to risk. Risktaking of the literary kind, of the political kind, of the emotional kind… The net result reminds me of the old playground joke. Q: How do porcupines make love? A: Very carefully! Modern humans feel the same, even when they're just writing about it. And maybe with good reason.