Ancestors do turn quear, as Daisy Ashford says, and when you begin the third novel of a trilogy without knowledge of its forerunners, your fear is not so much that you won’t know who the characters are, for any competent author can introduce you to them; it is that the novelist may have embarked earlier on some grand figurative device that is set to run and run, some complex allegory that you haven’t a hope of coming to grips with. But when you find that, on the first page, a man called Arthur Cornish is presiding over a board meeting at a circular table; that the trust fund over which he presides is discussing an opera called Arthur of Britain, or the Magnanimous Cuckold; then learn in the next chapter that Arthur (not the King) has developed mumps and swollen testicles; that the unfinished opera was allegedly the work of Hoffmann, who in turn was worked over by Offenbach, who provides – ah yes – the title of the book – you do not feel you are in the company of an author who is going to chain you in a pit of obfuscation. ‘The lyre of Orpheus opens the door of the underworld.’ Eureka. Nil desperandum. Light breaks where no sun shines.

It is easier on the reader when the characters themselves are slow on the uptake. If you cannot understand the significance of the sword Cali burn, neither, immediately, can Dr Gunilla Dahl Soot.

‘The symbolismus is very good,’ said the Doctor. ‘Aha, the sword is also Arthur’s thing – you know, his male thing – what do you call it?’
‘His penis,’ said Penny.
‘Not much of a word … Have you no better word in English?’
‘Not in decent use,’ said Darcourt.
‘Oh – decent use! I spit on decent use! And the scabbard is the Queen’s thing – what is your indecent word for that?’
Nobody quite liked to reply, but Penny whispered in the Doctor’s ear. ‘Middle English,’ she added, to give it a scholarly gloss.
‘Oho, that word!’ said the Doctor. ‘We know it well in Sweden … I see that this will be a very rich opera. More champagne if you please. Perhaps the best thing would be to put a bottle here beside me.’

The Lyre of Orpheus, quite comprehensible as a one-off, is linked with The Rebel Angels and What’s Bred in the Bone. The latter’s sinister aphorism rustles through this book: ‘What’s bred in the bone comes out in the flesh.’ Francis Cornish, ‘a very odd man,’ is dead. He was a painter, detector of fraud, and spy. The reader knows more of his life than the hapless trustees of the charity who administer his wealth. Robertson Davies treats his characters with a lofty blend of ruthlessness and compassion; he is a man who could swot flies, but who has devoted himself to the pleasures of entomology.

Arthur Cornish has a wife, Maria, and it is the custom of the men around her to fall in love with her. Her former teacher, Clement Hollier, is a scholar of medieval history, ‘possessed of a gloomy insufficiency as a human being.’ Geraint Powell is an actor and professional Welshman. The Reverend Simon Darcourt is another academic; he is writing Francis Cornish’s biography, and is destined for Merlin’s role in the narrative. The opera they decide to retrieve and perform proves to have little music and fewer words. They must reconstruct it according to their own natures. The dirty, ugly and rude young woman who undertakes to complete the score will finally fall in love, and swallow a hundred aspirin and half a bottle of gin; all along, despite her best day-to-day efforts to be repellently prosaic, her subconscious mind has her fingered as the Lily Maid of Astolat.

One of the characters reflects on the composer Hoffmann’s methods: ‘it’s so matter of fact, and then – bang! You’re right out of this world.’ This is Davies’s method too. He indulges his gifts for satire and parody; the dialogue is elegant and very entertaining, and beneath the narrative runs the thread of the author’s civilised, discriminating discourse with the reader. It is a clever book, with its self-conscious campus comedy; but we become aware that the author is, like his character Darcourt, ‘a significant explainer in a number of important worlds.’ When the characters get themselves into awful trouble, ‘superficial modernity of opinion’ hinders them. A reading of the tarot cards enlightens them more than the painful pursuit of logic. Gipsies and deceased monks sway the course of events. ‘Poor old Psyche! Poor old Soul! How our world was determined to thwart her at every turn.’

The author is a Jungian, and believes his readers to be no such thing; he battles for their souls too fiercely, in the centre of the book, and risks losing their attention. It is as if the characters, who are excellent talkers, have begun to chatter uncontrollably. Davies sends Darcourt to a woodland retreat to do some thinking; the author himself, in the likeness of Father Bear, stalks the forest paths of philistinism swiping with a great paw at everything that moves. It is as if he is arguing with a reader who takes some grim mechanist stance – some Pavlovian of the bookshelves, some dour materialist. But anyone who has got so far will hardly need to have their spirituality made over; except that Robertson Davies is a Canadian, and seems to have no great opinion of his nation’s inner life. Davies is also an optimist, and his motives are of the best: ‘mystic truth sets you free to do a lot of practical things.’

After Darcourt’s mid-book summary, the story is back on course; the staging of the opera is its climax. Masquerades arc its theme: representations, fakes, counterfeits, disguises, true and false art. It is an achievement to put the reader in a good mood on the first page, and leave him there after five hundred, and it will be surprising if a funnier or more absorbing book comes along this year. Someone quotes Keats towards the end: ‘A man’s life of any worth is a continual allegory.’ The characters find this an inspiring but terrifying thought; they believe it but ‘keep getting unconvinced.’ Perhaps Robertson Davies is right to drive his points home. After all, as Darcourt says, ‘my damn book will be on the shelves when all of us are dust.’