Donna Tartt is a wonderful writer. Look at how she arrived in 1992: “The snow in the mountains was melting and Bunny had been dead for several weeks before we came to understand the gravity of our situation.”

The Secret History more than lived up to the promise of that opening. It was a glorious combination of intrigue, in-crowd appeal, mystery and wrong-footing cheek. It was intelligent, fresh and a compulsive page-turner. It turned Tartt into a star and sold truckloads of copies, as did her next book, The Little Friend. After only three novels, she is one of the 100 most influential people in the world, according to Time Magazine.

Which goes to explain why editing Donna Tartt must be a daunting task. Why it would have taken steel cojones to ask her to trim down some of The Goldfinch’s 864 pages. Why no one would want to be the person to tell her that the last 30 pages of her novel are among the worst ever committed to paper by a serious writer. Not least because an editor with good instincts would know that Tartt was also clearly doing something right. This book, eagerly awaited for more than a decade (it was originally scheduled for publication in 2008), has done the business. It’s sold millions of copies. It got a rave review in the New York Times from the great Michiko Kakutani. It won the Pulitzer prize. Better still, Stephen King liked it. He said: “The Goldfinch is a rarity that comes along perhaps half a dozen times per decade, a smartly written literary novel that connects with the heart as well as the mind.”

I’m not about to disagree with Stephen King; not entirely. I’d maybe quibble about the “smartly written”, although there are undoubtedly some fine moments of drama and of comedy. But there’s no doubt that this book does connect with the heart and mind.

Just in case you aren’t among the millions who have already read the book, here’s a quick summary. Theo Decker is 13 years old when his life is blown apart, in a very literal sense. There’s an explosion in a gallery he’s visiting with his devoted, angelic mother. She dies; he escapes with minor injuries and carrying a priceless painting from 1654 called The Goldfinch. He’s taken this masterpiece because a dying old man who ended up beside him after the blast told him to do so. This man also gave Theo a signet ring that leads him to the house of a charming old furniture restorer called Hobie – a place that becomes a safe haven as Theo tries to come to terms with his loss and deal with his alcoholic and chronically unreliable father, then falls into his own spiral of self-destructive behaviour and substance abuse. Oh, and fails to return that rather important painting to the proper authorities...

Theo, the narrator, is an admirably unlikable character. He’s flawed, selfish and does very silly things. But Tartt gives him a strong sense of decency underneath it all and surrounds him with some lovable creations. Hobie is a fine old gent, while Theo’s friend Boris can at his best set the page alight with all the fire of a Betsey Trotwood or a Falstaff. He’s a fantastic rogue, swaggering, swearing, half-cut and all heart. His catchphrase is the splendidly insouciant “fuck it”, and I fell for him almost as hard as Theo does.

Meanwhile, there are those cerebral rewards that King referred to. This is a novel that references Antoine de Saint-Exupéry’s mighty Wind, Sand And Stars , that asks fascinating questions about human fallibility and culpability, that has a great deal to say about the way we value art - both financially and as a measure of human achievement and the human soul.

But it’s on this latter point that the problems crowd in. When I write “a great deal to say”, I mean it. There are pages and pages of dull theorising and cod-philosophising. And then, just in case you miss it first time, there’s a great clump of useless explanation at the end of the novel, tacked on after the action concludes.

There are other large sections of the book that seriously drag. The Goldfinch has stirred up quite a bit of controversy, with critics such as James Wood saying its success represents “further proof of the infantilisation of our literary culture”, and howling that the emperor has no clothes. The fight - as explained in this fine Vanity Fair article - is often portrayed as one between readers who understand the value of good old-fashioned entertainment and snotty critics who want something more serious. But my objection to The Goldfinch isn’t to do with not being smart enough, but that too much of it is dull.

At its best, The Goldfinch has that cosily addictive quality of a good old Victorian doorstopper. It’s often been compared to Dickens, but with its air of mystery, intrigue and dastardly doings it reminded me more of Wilkie Collins. At its worst, though, it’s torturous. For great chunks of the book Theo just mopes about his mum and ingests opiates in an unconvincing manner. There are long descriptions of where he’s scoring the drugs, what he’s taking and how, but he never feels like a real addict, since he is able to switch his obsession on and off as the narrative requires. Meanwhile, the more active sequences are bloated. Boris and Theo spend dozens of pages having laboriously described homoerotic fights. It takes 50 pages for the air to clear after that initial bomb blast. Another 50 are spent describing Theo’s “fever haze” and “sweat-soaked sleep” after the (silly) climactic gun fight.

That “sweat-soaked sleep” brings me to the next problem. The writing is full of cliche. Theo is forever “haunted” by scenes from his past. He’s always “reeling” or “torn-up”. He talks about the “tip of the iceberg”; his heart “leaps for joy”.

Let’s not forget either that the premise is entirely absurd and the plot overloaded with coincidence. Why did the old man ask him to steal the painting in the first place? Why is it that nearly everyone Theo meets is so into art? How is it that he keeps bumping into people he knows at just the right moment in a city as big as New York? None of this is ever adequately explained. Notice I say “adequately”. Everything seems to be explained at least three times, but that isn’t the same thing.

In short (possibly the wrong phrase to use in the context of The Goldfinch), and in spite of Tartt’s talent, this is a deeply flawed novel. And yet, it goes from triumph to triumph. In 2012, the judges declined to award the Pulitzer prize because they claimed to be unable to find a book of a high enough standard, even though Train Dreams, which already feels like aclassic, was right under their noses. In 2014, the same prize went to The Goldfinch. The universe mocks us. If this novel wins the Not The Booker prize too it’s going to feel like another cruel joke.

Next time: the vote