John Boyne is a classic example of an author who writes a book so huge that it overshadows everything else he had done before and will ever do again.
In his case, that book was The Boy in the Striped Pyjamas, his first children's book, which sold millions. If he never wrote another book after that, his place in literary history would already be assured.
Less successful writers have every right to look on enviously; but many who do find themselves in that fortunate position often complain that the work for which they're best known can become an albatross around their necks, and few ever manage to produce another as striking.
Boyne may have bucked the trend with his new novel, his 12th for adults. The title of A Traveller at the Gates Of Wisdom may make his book sound like some sub-Paulo Coelho mystic word salad, but it's a hugely ambitious saga whose plot spans 2,000 years and does more in its 400-odd (sometimes very odd indeed) pages than many writers achieve in their entire careers. There's a but, and it's a huge but; but we'll come to that in due course.
It begins in Palestine in AD1. The narrator's father is a Roman soldier sent out to slaughter newborn baby boys in the towns around Bethlehem on the orders of King Herod.
The same character then keeps reappearing at various points in time, on all continents and through all periods of history - Guatemala in 420, Sweden in 1133, India in 1385, Japan in 1743, culminating in the USA in 2016, followed by a further episode 60 years in the future, fulfilling the prophecy 200 pages earlier, in 13th century Greece, that he would live "among the stars".
It sounds fantastical, but it has been done in various forms before. Think of the TV sitcom Blackadder. The same characters keep popping up at different points in history. That one also zips forward to the far future. The story here follows in a single narrative that just happens to be broken up by long stretches of time. So, in 800AD he is at the monastery in Kells, where the monks are at work on their famous book, though he himself is not a monk, and doesn't think God exists. Next time he appears, it's in a different monastery in Nepal 62 years later, where he's still not a monk and doesn't think Buddha exists. Then he's in another temple in Indonesia in the year 907, the same soul in multiple incarnations.
Some of the situations in which the narrator finds himself are tragic, others comic. He even meets Lady Macbeth in what can only be described as peculiar circumstances. "Some killings are justified," she tells him. Well, she would say that, wouldn't she?
In an age when cultural appropriation has become such a bone of contention, it's a bold move to take on the personas of so many people from different cultures which are not one's own, but Boyne does so without fear. To insist on the oneness of identity at a time when self-identification has become fractured into ever smaller units of difference is equally audacious.
Sometimes the novel feels like a travelogue, skimming on the surface rather than delving deep into the periods and cultures it is rooting among; and there is always the risk that some chapters, each a short story in its own right, will fall flatter than others. Sometimes too the interwoven themes of colonialism, conquest and relations between men and women are touched on too cursorily. The last two centuries - during which a lot has happened, to say the least - are passed over in only about 50 pages.
But the sheer verve and ambition of it all dispels any doubts. It bears comparison to David Mitchell's Cloud Atlas, which also ranges across various civilisations and time periods, but this one is more accessible. It's apt too that it ends in space, tying into the latest ideas about quantum physics and everything being connected, and nothing only being one thing.
Now here's the but. It comes in the final chapter, which centres on the 2016 election of Donald Trump. It's crude, cartoonish, didactic and heavy-handed. It hits the reader on the head with polemic where the earlier sections had teased them with allusion. The parallel between King Herod at the beginning, slaughtering the holy innocents, and Trump at the end couldn't be clunkier.
What follows is an epilogue which, if anything, is even worse, containing a scene of such childish wish-fulfilment that it beggars belief that Boyne's editors didn't beg him to take it out. It's rare to see an author set fire, literally in this case, to his own painstakingly constructed narrative, all for the sake of a cheap joke.
After persevering through thick and thin for hundreds of pages, it's hard not to be cross with Boyne for not having the patience or discipline to make his final point more subtly; but it's his novel, and he can do with it whatever he likes. It's still worth reading, just slightly less magisterial than it might have been.