'I go to the cinema,' said Kay; 'there's nothing funny about that. Sometimes I sit through the films twice over. Sometimes I go in half-way through and watch the second half first. I almost prefer them that way - people's pasts, you know, being so much more interesting than their futures. Or perhaps that's just me...'(The Night Watch, Sarah Waters)

I've never really believed in the romance of Romeo and Juliet, although I have to say I'm quite into the dick jokes of Elizabethan youth culture. But the lovers, with their morbid obsession with death and their emotional hysteria in the face of the slightest provocation, seem to possess all the grand tragedy of a couple of teenage goths. I did, however, cry once, at, of all things, the Zefirelli film. It has this wedding scene bunged in there and the eye-liner daubed lovers look at each other meaningfully, full of hope and anticipatory and blissfully unaware of the inevitable tragedy awaiting for them. The sheer weight of dramatic irony was simply too much for me, and I broke.

The reason I mention this at all is that I inadvertently exposed my tender, irony-sensitive heart to a bucketload of it when I read Ellen Kushner's Riverside books out of order. They're definitely not meant to be read that way but they are sufficiently self-contained that you can. And, oh dear, it nearly undid me which is, in itself, slightly peculiar because I got the end of the second one (The Privilege of the Sword) and was pleased but not passionate, read the short story The Death of the Duke out of vague curiosity and then hysterically wept my way through the first book, Swordspoint last of all. I think the problem is that fictional characters usually don't have much by way of context: they die in the text or they don't die, in which case they live forever in your mind, as the people they were in the book. Knowing that a future -- and death, in the inevitable rather than the violent sense -- awaits a character beyond the pages of the book you are reading is a bizarrely moving experience. I'm just a sucker for the bittersweet.

Swordspoint self-identifies as a "melodrama of manners" and The Privilege of the Sword is its sequel, set in the same nameless, pseudo-Georgian city a generation later. Swordspoint follows the adventures of the master swordsman, Richard St Vier, and his mysterious, half-mad lover Alec, as they pursue trouble and glory on the mean, crime-wracked streets of Riverside. As perhaps the most accomplished swordsman of his day, Richard is highly sought by the aristocrats of the city (who reside safely on The Hill, protected from the denizens of Riverside) and he and Alec find themselves draw into a web of political and sexual intrigue. The Privilege of the Sword follows Alec's niece, Katherine, as a seemingly mad whim of her Uncle forces her to abandon her dreams of parties and pretty dresses and, instead, learn the sword. Again, there is intrigue. And also vengeance. Yum.

It's difficult to talk about both books without dropping enormous spoilers, in the sense of information that could genuinely spoil the pleasure of reading rather than in the sense of arbitrary information about the plot. The relationship between Richard and Alec has been established before the opening the book but the fact that Alec, with his sharp-tongue, his posh accent and his self-destructive urges, does not belong in Riverside is very clear. Of course, I knew who he really was from the beginning which denied me a denouncement but illuminated what I knew of his character from The Privilege of the Sword. By the same token, I didn't realise the villain was, you know, The Villain until about halfway through Privilege which, again, has probably interfered with my reaction to the books. I'm not sure whether it's a direct consequence of having read them out of order but it seemed to me that the books are not so much sequels but complements, rather like two partially broken mirrors facing each other. And, although I found Privilegeon its own pleasing but not necessarily outstanding, by the time I had read both books I was utterly captivated.

Part of the reason they are so compelling comes down to the style. My version of the book has a cover that's almost completely obscured by an embarrassingly gushing quote from George RR Martin, a man not exactly renowned for his elegant prose. But the style of Swordspoint and Privilege seems to be somewhere between the mannered and the pedestrian, a mixture of the rhetorical and the everyday, for example it begins with a self-consciously fairytale image of a drop of blood upon some snow which transitions seamlessly to the quotidian: "The hero of this little tableau has just vaulted the garden wall and is running like mad into the darkness while the darkness lasts." It occasionally slips and strains but it works for me. The narrative is cruel and playful, exposing the vulnerability of and hypocrisy of its characters, while it's highly stylised nature distances the reader from the action so it feels as though you're watching event takes place rather than being caught up in them. Whether you consider this a strength or a failing probably comes down to personal preference, but it is definitely in keeping with the mood of the book and the brittle, violent, artificial world the characters inhabit.

The narrative twists and turns, leaping rapidly from character to character, offering flashes of detail and momentary illumination. This is one of the most tantalising aspects of the book. For example, by the time the book begins Richard and Alec's relationship is already well-established and, although Richard occasionally reflects on their first encounter, the reader never learns the details of it. Similarly, in the first book, the manipulative Duchesse of Tremontaine remains opaque and intriguing throughout. And why does the villain (for whom I have a great deal of appreciation, even though he's vile) only have one eye? The book is full of small mysteries, which only serves to make the characters more compelling and the occasional insights offered all the more exciting.

Most of the characters the reader encounters are morally ambiguous, but they are presented with sufficient subtlety that it never feels as though A Point Is Being Made and you find yourself rooting for them anyway. Richard is a little more than a murderer, and his detachment runs perilously close to the sociopathic. Alec is a sharp-tongued, cowardly scholar with a death wish. Up on the hill, The Duchesse plays her political games with extraordinary finesse but reveals very little humanity at all. Lord Horn is a lust-driven fool. Lord Ferris plays the Machievel and his villainy is only differentiated from the equally base drives and desires of the surrounding characters because it happens to become tangled with the fates of Alec and Richard. In fact, the only reason one can identify him as a villain at all is because he gets caught. He does down magnificently though. No, not like that! He makes a comeback in Privilege but by then he really is completely and unambiguously nasty and I was disappointed.

Richard and Alec are different only in that they love each other, and set against the harshness and the hypocrisy of their world, the moments of genuine emotion and vulnerability they share are deeply touching. The murderer and the nutter with the death wish: they make a lovely couple. Joking aside, they are perfectly suited, bringing out both the worst and the best in each other. Of the two lovers, Alec is the one that troubles me the most. He's almost a mad, bad gay cliche (in the Felix Harrowgate mould) and I think his creator is more than a little in love with him. He got on my nerves a little -- particularly in Privilege in which he no longer has Richard to temper the worst of his excesses " but I think I secretly liked him anyway.

The mere mention of "dark fantasy" is surely enough to make most self-respecting fantasy readers roll their eyes in despair but Swordspoint and Privilege fit the bill nicely, not because they lack humour (indeed, they are often very funny) but because, beneath the glittering and stylised surface, the world is one of casual cruelty and everyday violence, depicted subtly and without pretension. The books aren't perfect. Privilege bogs down a little in its own political agenda and the pacing of both is often quite irregular, with main characters being side-lined for chapters at a time. Some readers may find the self-consciousness of the language and dialogue a little off-putting (although how anyone can resist a line like "now he was caught on the gilded curlicues of his own plot" is beyond me) and the fragmentary glimpses of the inner life of the characters frustrating rather than tantalising but I was very impressed with Swordspoint and, probably, also with Privilege although I am probably going to have to re-read it now that I understand the backplot. I'll miss the dramatic irony though.