This book, a sprawling, Grisham-like legal thriller set amid the affluent, east-coast African-American community, was a legend before it rolled off the presses. American publisher Knopf broke records by bidding $4.2 million for it and a follow-up.

Now, on its publication, the new Today book club (which has stepped into the breach left by Oprah Winfrey's decision to cut back her book-club recommendations) has chosen it as its first title. This has sent the publisher scrambling to the printer for a further 250,000 copies, bringing the total to half a million in its first month.

Was it worth it? It appears it was for the publisher. Other than that, it seems unfair on the author to speak of the value of his book in those terms (although he has done very nicely, too). But he was already doing very nicely.

A Yale law professor for two decades (although he must still be only in his mid-40s) and with six highly regarded non-fiction books to his name, his hugely successful foray into fiction will only ensconce him further in the lifestyle and social milieu he so convincingly draws on in his novel.

This is a big book - 650 pages - and takes its own time to get through. Whereas with a Grisham novel your fingers are kept fairly busy flicking over the pages, with Carter's expect slower progress.

The pages teem with characters, subplots and moral conundrums and you can't afford to ignore any of them.

The labyrinthine plot twists through pockets of society we scarcely knew existed, through backways of the mind, around riven and struggling relationships and through the strata of United States political, legal and academic life.

And beneath the crowded stage is the undeniable chasm of loneliness - of being alone in a crowd - that indeed seems to underlie American society and often its literature.

Our hero - a law professor at a top-notch university - reflects matter-of-factly at one point on "how friendless an existence I have managed to create".

The book is full of people who will not disclose information, who do not reveal emotion, who engage in various kinds of subterfuge.

Our hero, collecting and deciphering clues about his father's death, holds information close to his chest and muses that "the weird part is that there is nobody to tell".

Talcott Garland is the second son of Judge Oliver Garland, a ferociously conservative black judge who would have made it to the Supreme Court had not a scandal erupted around him at the last minute, ruining him politically and forcing him to retire.

As the book opens, the judge is found dead in his study, apparently of a heart attack and at his funeral Talcott is approached by a shadowy friend of his father, "Uncle" Jack Ziegler, who demands that Tal tell him about his father's "arrangements".

Tal is shaken and mystified by the underlying threat of Ziegler's approach, and things start to snowball. An old aunt makes a strange comment; he is visited the day after the funeral by two FBI men also inquiring about his father's "arrangements" - and so begins a cryptic mystery, in which Tal understands nothing, but is increasingly sucked into a mire of danger, violence and uncertainty.

He finds an ally in his sister, Mariah, a conspiracy theorist who trawls the internet for sites speculating about the causes of her father's death (the judge is a major figure in American society) and who is married to a white financial mogul.

Through this and adding considerable stress to Tal is his foundering marriage to Kimberley (Kimmer): a gorgeous, super-ambitious legal whizz who has been nominated for a judgeship.

Kimmer appears resentful of her marriage, and takes out her frustration in a number of affairs, united with Tal only in their mutual love for their 3-year-old son Bentley, whose presence in the book is as a receptacle for finer feelings of love, and as a symbol of innocence and all that could be lost or damaged by the encroaching evil.

Carter's skill lies not just in his superb management of the complex plot, which has as its motif a particularly complicated chess manoeuvre, but in his ability to sketch a state of mind, or a dilemma: how successful, affluent Blacks feel about their position in a society they will never completely conquer or feel wholly a part of.

For a thriller, the pacing is frustratingly slow at times, as Carter indulges his delight in character construction.

But if you weren't trying to review it, and therefore struggling through as quickly as possible, you could probably relax into this discursive style and simply enjoy the slow escalation of tension and danger.

Jonathan Cape