A CHARISMATIC but wayward hedonist abandons an easy life in a successful business, only to be dragged back a few years later. You could try to draw parallels between the barebones plot of The Steep Approach To Garbadale and the recent career of its author, but it would be a stretch. The book may come billed as "Iain Banks's first literary novel in five years, " but that sounds suspiciously like a line spun by a marketing department more used to coping with his phenomenal writing rate (he averaged a book a year from 1984 and 2000).

So the tacit suggestion that he has been agonising for years to compose his latest is a little cheeky. But once you crack the book open and reacquaint yourself with his confidently freewheeling style, it hardly matters.

Perhaps it helps that The Steep Approach To Garbadale contains echoes of The Crow Road - probably his most-loved book. Again, there is a Scottish family whose tangled history is wrapped around a furtive secret, with a young man trying to hack his way towards the truth. Alban McGill is a thirtysomething who knows how to handle a chainsaw (though his recent exploits have caused him to develop "white finger, " the repetitive strain injury of lumberjacks).

Alban's surname disguises his link with the Wupold family, creators of a boardgame called Empire! , whose profitable popularity has spanned more than a century. Having turned his back on the family business, Alban gets dragged back when an American company targets Empire! for acquisition.

An extraordinary general meeting of shareholders at the family seat of Garbadale is called, coinciding with the 80th birthday of the formidable Wupold matriarch, Win. Alban is tasked with drumming up opposition to the sale, travelling around pricking the consciences of long-forgotten relatives.

This sudden re-establishment of contact with his clan picks the scabs off Alban's painful early memories of his mother's suicide and his intense relationship with his cousin Sophie. Alban's teenage perception of their love is hopelessly mind-bendingly romantic but Banks doesn't shy away from the more sticky manifestations of adolescent exploration.

This close juxtaposition of high-minded romantic ideals and the slightly more prosaic nature of their physical expression is as much a Banks trademark as his more obvious Top Gear tropes (fast cars, whisky, computer games and name-dropping hip Scottish bands). But it's also perhaps one of the keys to his enduring appeal; who hasn't tried to legitimise their desires by attributing them to some abstract higher power?

Upon discovery by their horrified parents, the kissing cousins are firmly torn asunder, though Alban continues to nurse feelings for Sophie, poring over his dimming teenage memories like religious relics. Despite this, he has landed a slightly implausible girlfriend - a towering, self-possessed blonde German mathematician with an enviable sexual appetite who loves him but doesn't want to marry him, and can match his postcoital wit one-liner for zinging one-liner.

On paper, Verushka Graef sounds like she'd be more at home in Banks's utopian sci-fi universe but she becomes one of the book's most human characters when, unbidden, she relates how she survived the Stephen's Day tsunami of 2004.

Her rapid account of being in the water when the sea suddenly chills and then churns is urgent, powerful stuff, achieving, in a few pages, a movingly resonant response to world-changing events than the whole of Dead Air.

The plot's grind toward Garbadale, Win's 80th birthday and the family revelation might seem a little schematic but Banks spools freely back and forth through Alban's life - a series of sparky, self-contained episodes and assured character sketches that represent the sort of amplified, wittier version of real life that Banks seems to wish we all lived in.

Nobody can evoke the mindset of a self-obsessed, sexually active, mildly philosophical thirtysomething as convincingly as Banks and it's terrific to have him back. But he's just turned 53 - is it too much to want him to reach further into life?