Although his literary works are by no means uniformly successful, Peter Ackroyd may safely be described as an author possessed of genius, and had he died before attaining middle age (like Bruce Chatwin, say), he would doubtless have been the subject of an admiring industry fussing over his prodigious achievements. But the life that he once admitted had been sacrificed to the cause of literature continues unflaggingly: biographies, poetry (often strange), riddling fiction, a book on transvestism (nice pix), a journalistic output embracing criticism of film and television, plus a long stint as chief book reviewer on a daily paper. And did I mention he was originally a rocket scientist and is a world-class player of the krummhorn? Well, you never know.

You also never know quite what he will come up with next, and even the most devoted Ackroydist might not have predicted anything so gracile and strange as his tenth novel. For one thing, The Plato Papers is catwalk-thin. It is also set in the distant future, which is something of a departure for a novelist who has so pioneered the notion that the past need not appear a foreign country. Mind you, his London, some 1,700 years hence, is definitely shaded with fourth-century-BC Greece, and adhering to strict notions of historical period will prove a disadvantage if readers want to relish the ludic, fin-de-siecle spirit on which much of the book depends.

Visual clues are tantalisingly scarce, but we are invited to imagine a human population that has evolved into an ethereal race dwelling in a rarefied state of air and angels, having escaped the tyranny ·of linear time and the false idols of science. The book comprises fifty-five shards concerning the life and teachings of a London orator named Plato, who is trying to deduce what life was really like in the unenlightened ‘age of Mouldwarp’ (ie the present day). His speculations are disconcertingly false, as the cultural evidence that has survived is itself so fragmentary. Thus, the novelist has a deal of fun with the pitfalls of historical detective work. This could be read as a gloss on his own fictional methodology and the essential idea of the unreliable narrator. (Don’t take my word for it, though.)

Poor young Plato does his best, but his sources are frequently curdled: The Origin of Species by Charles D is interpreted as a comic novel by Dickens (there are anecdotes about another comedian, Brother Marx); a copy of Poe is taken as a blueprint for the entire North American lifestyle (‘the passages were lit by candelabra’); and a clip of Hitchcock’s Frenzy is used like a palimpsest to describe ancient London. This will have to suffice as a plot summary.

The novel is accordingly interlaced with a certain Martianism which is ingenious but perhaps no more than a conjuring trick. Featured in the early sections is a glossary of antique terms which is entertaining enough – Ambrose Bierce meets Brian Aldiss – and allows our author to evoke an excellent image of the Mouldwarpian epoch as purblind and literally subterranean (Plato believes it is the underworld). Thus we are treated to definitions such as ‘logic: a wooden object, as in log table’, and ‘echology: the practice of listening to the sound of one’s own voice, as if it then became of greater importance’. This brand of smartness can grow tedious, but it forms just a minor component in the mosaic picture Plato is assembling of our dystopian age. Mouldwarp (AD c.lS00-2300) was a time of ignorance and ‘shadowy violence’, characterised by the fetish for information and speed, an era that culminated in the stars and sun going out and humans rediscovering their inner light (listen, I’m just the reviewer here). This was succeeded by the Age of Witspell, wherein the world was suddenly alive with mythical creatures – kraken, unicorn, phoenix – and legendary places such as El Dorado and Avalon reappeared. (A Slough of Despond is discovered on the border of Wales, just one silly joke I enjoyed.)

If all this sounds a tad tonto, there are elements that aficionados will find familiar. The author’s skill in pastiche is once again evident, especially in the sections of dialogue between his interlocutors Ornatus, Sparkler and Sidonia (who is what Swift would have called a ‘Platonne’), and in the arch and archaic sounding conversations Plato enjoys with his immortal soul: ‘Do you always ask questions? It may become irritating.’ Add to this that the novel alludes subtly to London, a subject that seems to bring out the best in Ackroyd, and there is much to savour. When a remnant of The Waste Land is unearthed (typically misattributed to George Eliot) we can enjoy witnessing T S Eliot’s biographer poring over the fragments and piecing together his own underworld, an unreal city that is distorted but recognisably ours.

This thoroughly eccentric book is due to be published on the last April Fools’ Day of the millennium. It is full of esoteric flourishes and delicious strokes of fancy (‘Shall we take a skiff down the Fleet and search for angels’ feathers?’), and I suspect its appeal may be limited. But still, the hardback is sure to be a smart fashion accessory this spring. I suggest you tote your copy of Plato whenever you drop in on The Academy.