"Twenty primary feathers and the blue dome of the sky"

The idea of a genre of fiction called 'fantasy' has always appealed to me. It seems to suggest a kind of fiction with little or no basis in reality, where you can invent whatever worlds you want to, populate them with the strangest creatures you can conceive of and throw all the rules of the real world out of the window.

And yet the fantasy section of every bookshop is merely full of books about the same old dragons and knights - backwards-looking books that are obsessed with outdated notions of chivalry and social status. Well, bookshops be damned. After waiting for what seemed like forever for it to come out in paperback, I ordered the third in Steph Swainston's Fourlands novels - The Modern World - from Amazon, and, once again, I'm faced with the stark narrative power that comes from placing realistic characters in highly imaginative situations.

The Modern World opens with our dazzling anti-hero Jant - part of the Emperor's Circle of immortal paragons and the only man who can fly - in his strangest situation yet. That is: completely clean of drugs and in good health - bar a few post-traumatic flashbacks to the time he was eviscerated by giant insects. It doesn't last, of course. A new plan to rid the Fourlands of its pesky six legged monsters is being put into action, and Lightning, the Circle's archer and Jant's closest friend in every way except name, has lost touch with his teenage daughter in the grimy city where Jant first got hooked on his drug of choice.

The Modern World capitalises on the careful characterisation of the previous two books to deliver some shattering turns of plot and emotion. Giddy flights of imagination are fleshed out with down-to-earth realism; snappy dialogue provides keen observations on both the fantastic and the mundane. People we're familiar with from the first two books are shown in surprising new lights. Rayne, the Circle's doctor, is an unexpected new focus: immortalised in her old age, mild-mannered and open-minded, dedicated to advancing the cause of medicine even as other doctors dedicate themselves to stealing her place in the Circle.

Events build up to a catastrophic climax, as you'd expect. But there's still a fair few chapters left, after things have wound down to a much more serene pace. At first I thought this was the result of an authorial miscalculation, a narrative misstep. But these last chapters calmly deliver probably the most profound and heartbreaking scenes so far in the series - in the process upending one of the Fourlands' most obvious assumptions, and bringing tears to my eyes.

I've enjoyed all three of Swainston's Fourlands books so far. If more people paid attention to them, they could herald a more sophisticated, self-aware and imaginative form of fantasy. These are books that flirt with our nostalgia for bygone eras and muse about when to let go. These are books that cast the human condition in a strange new light against surreal new backdrops. And if that doesn't appeal to you, these are also books where a winged junkie dukes it out with man-sized carnivorous bugs.