In its most recent paperback sales round-up, The Guardian was forced to conjure with a wholly new publishing genre in amongst the thrillers and romances - X-Files. In the four seasons since its inauspicious debut at the end of 1993, The X-Files has become a full-fledged, gilt-edged phenomena; shelves groan under the weight of sheer mind-rotting toss made marketable by the mere addition of that enslaving 'X'. Disappointingly, however, this latest is unlikely to feature in next year's Guardian. It has no pictures (save the 1961 cover-shot of an ultra-grainy UFO), no profiles and, thank the Lord, no attempts at examining the 'truth' behind the weekly silliness. This is Manga's God-awful comic reimagined by Sight & Sound, written by, whisper it, academics.

The blurb informs that this is the first real attempt to "examine the significance of the show", but by the end of the last - "the imaginary, voyeurism, and the Symbolic Order in The X-Files" - these essays still leave us slightly frustrated. We want to know, as the rear-cover hints, why the show has ripened under a Clinton White House, and why its nearest (and better) neighbour, Twin Peaks, "belonged to the Bush Presidency". The eleven pieces in here are in that sense as annoyingly inconclusive as the programme itself.

The keys are three to unlocking the truth of Chris Carter's baby, not the least of which (and the only one this book really tackles) being it's realignment of genre-gender roles. As Willcox and Williams point out in their entry, the show subtly exchanges designated roles for its male and female agents (he becomes intuitive, she pragmatic), with paradoxically subversive and reactionary effect - since most of the supernatural/ufological content is shown to be genuine, Scully inevitably comes off second to the Mulderian thirst "to believe". There is, however, enough insurrection over traditional TV gender roles to permit genuine access to female fans, especially, as Susan J. Clerc notes, in Internet discussion groups. (As much as one quarter of on-line traffic is apparently female in origin.)

Curiously, 'Are You Now or Have You Ever Been?', Graham's examination of conspiracy theory - our second key - steadfastly avoids making the obvious association: conspiracy is big business. Kick-starting with the JFK assassination, moving onto Watergate and ending in 70s conspiracy cinema, she somehow sidesteps the programme's central all-things-to-all-people message. The point, surely, being that collusion and connivance belong neither to Left nor Right; the JFK industry, for example, informs both, depending on your vested interest. That's as true of the mysterious smoke-shrouded cabal at the heart of Carter's show as it was of the granddaddy of Paranoia-TV: The Prisoner.

If anything it's the Right who have laid claim to conspiracy in the 90s - a true corollary of Clinton-hood? - from Waco to Oklahoma to the bombed-out abortion clinic. "The Government is lying," that mantra of Vietnam-era liberalism, is now equally barked by its sworn enemy. Everyone is convinced that Capitol Hill is hiding something and no one, it seems, subscribes to the cock-up theory of history. The X-Files brilliantly taps into that climate of distrust: paranoia sells. In that, as Graham has it, the best place to look for antecedents is surely Alan J. Pakula's brilliant 1974 thriller The Parallax View, wherein the great political upheavals of an era are traced back to the sinister, enigmatic Parallax Corporation. (Likewise, although it's not mentioned, William Richert's little-seen black comedy Winter Kills, from 1979.) The big change, of course, is that Carter has elected to use FBI agents as his pawns in place of Warren Beatty's investigative reporter - something Michele Malach tackles in her useful 'I Want To Believe...in the FBI'. It's a decision readable either as sinister (the Government investigates its own) or merely practical (easy access to resource and authority). Of course, the possibility still exists that Government has little to do with the central conspiracy itself (whatever that actually is), but Carter - who calls Watergate "the most formative event of my youth" - has successfully smudged the line on what Noam Chomsky has labelled "organised forgetting".

(This is one reason why Files-wannabe Dark Skies is selling us such a pup. A humourless show-off little brother, it places its protagonists outside of a real power-base, thus rendering their pursuits too accidental; a veritable Invaders for the 90s. This allied to po-faced scripting, laughable quality thresholds, and acting - the great J.T. Walsh excepted - too often on the wrong side of competent. The X-Files is postmodern enough in some of its very best episodes - Syzygy, Jose Chungs (sic) From Outer Space - to spoof itself. In a suicidally self-defeating decision, Dark Skies is cannabalistically self-satirised from its pilot on in.)

The third and final reason for X-success (and this really is no conspiracy) is the show's serendipitous surfing the early Fortean waves of millennialism. Previous centurial turns bore witness to religious fruitcaking and mass anxiety, sagged under the weight of end-of-the-worldists who, shamefacedly, wake just as hung-over as the rest of us come January 1st. But that doesn't prevent attempts to read the '00' with greater significance, and it's from there The X-Files draws a core audience. If - as seems increasingly unlikely - Carter takes his show over that imagined border, it won't survive on the other side. (Is it any accident that his newest, far darker offspring was conceived under the moniker Millennium?)

The X-Files has been remarkably prescient when it comes to hooking its rubbery Hammerism (Tooms, Fluke, the Jersey Devil, the incestuous mutants of Home) to some headline-courting scientific monkeying. All its makers need do is have Scully don her cute little round spectacles; a lap-top and high-power flashlight have taken the place of Peter Cushing's Bible and crucifix. But outside of the cumulative conspiracy (the so-called metatext that, incidentally, will eventually do for the show), what is there that we haven't seen a dozen times before? Elizabeth Kubek calls this the show's epistemophilia - "the desire to know" - contrasted with the network's dollar-snaffling need to shut resolution firmly outside of the door. Too many viewers, disappointingly, want too readily to believe; how else to explain Jane Goldman?

So is The X-Files, as one essayist in here claims, "the most subversive show to hit American television"? It surely fudges too much for that - even Dark Skies names names, no matter how silly - and, for all it gives us strong female characters, it's still men who dominate (how many shows does Gillian Anderson carry alone? how many women writers/directors?) Several names in this book were also involved in Full Of Secrets, the Twin Peaks reader, and that show is inevitably cited over and over in these pages. The Lynch/Frost ultimately failed because it was genuinely disturbing and truly subversive; it meant it where we are never sure that this show, with its cheery "I made this!", does. Lynch/Frost played it straight (and included that much needed closure, no matter how out-there) and lost as a result. Chris Carter too often wants it both ways and as a result we sense the much vaunted truth really isn't out anywhere. Only when it chooses to play with our preconceptions (Humbug, Jose Chung, E.B.E.) does it come anywhere near the best of Peaks.

Whatever its faults, Deny All Knowledge takes on some of this, questioning and analysing (a little humourlessly, excepting Alec McHoul's How To Talk The Unknown Into Existence) the show's methods and motives to some illuminating effect. As such it remains the only book so far written under the 'X' imprint that merits much more than cursory attention.