Carpentaria, by Alexis Wright

From its opening lines, Carpentaria is never going to be your average novel. Starting before time began, it explains how the land was made: "The ancestral serpent, a creature larger than storm clouds, came down from the stars, laden with its own creativity..."

This is epic, biblical stuff. The serpent creates "mighty bending rivers" across what is now northern Australia. It "spurns human endeavour in one dramatic gesture". The port town of Desperance, built in colonial triumph, is stranded when the river suddenly changes course. Human enterprise stands for nothing amid these vast and ancient natural forces. That's a given in the Aboriginal Law handed down through the ages, but to the whitefellas of Uptown, and to modern British readers, it all comes as a bit of a shock.

This is to say that it takes a bit of a brain readjustment to enter the world of Carpentaria. Alexis Wright, descended from the Waanyi people, says she imagined it as the voice of an old indigenous man telling stories. Her writing has obviously grown from an oral tradition, but storytelling is more essential to it than that. Here, stories are landscape, landscape is history, history is the Aboriginal people and the people are stories. "One evening in the driest grasses in the world, a child who was no stranger to her people, asked if anyone could find hope," begins chapter two. "Luckily the ghosts in the memories of the old folk were listening, and said anyone can find hope in the stories: the big stories and the little ones in between. So..."

Wright is not just telling a story here: this is every story. It's the story. To call it ambitious would be a hopeless understatement. It is ludicrous and maddening. By any normal criteria the plotting is absurd, the narrative is all over the place and dozens of characters go missing somewhere in its pages. It is a huge, audacious, monstrous work of genius - moving, uplifting and very funny. So...

The hero, since a story must have a hero, is Normal Phantom: patriarch, old man of the sea, weaver of tales and embalmer of fish. He is the leader of the Westsiders, who live in the Pricklebush, separated by an atavistic feud from their rivals on the east side of Desperance. Norm is friends with Elias Smith, who washes up on the beach one day with his memory lost somewhere in the Dreaming time. His enemy is Joseph Midnight. His wife is Angel Day, who may or may not have caused the separation of east and west with a painted statue of the Virgin Mary. But afterwards she left Normal for Mozzie Fishman, a spiritual zealot whose rusty convoy of followers endlessly travels the Dreaming tracks in clapped out cars. With him is Norm and Angel's son Will, a visionary who perceives the menace of the Desperance mine. And Will, eventually, is married to Hope.

The novel is teeming with characters, who drop in and out to great comic effect: the judge who disappears to Surfers Paradise; Father Danny, the boxing Irish priest; Lloydie, the barman who is in love with a mermaid trapped in the wood of his bar. "Invisible things in nature made no sense to Uptown because of their savoir faire in being Australians," thinks Elias, as the townies hail him as some kind of Messiah. But the real saviour is Will, who turns from Adam to Noah as Desperance is razed by an almighty flood.

As well as the Bible, a history of literature in English is here in these pages. Will is a Piers Plowman or Lemuel Gulliver among the faithless townies. Norm's ancestral knowledge of maritime mythology takes us from Robinson Crusoe via The Rime of the Ancient Mariner to The Old Man and the Sea. Fishman's convoy sounds like an ancient precursor to On The Road. There are echoes of One Hundred Years of Solitude and The Life of Brian. With an environmental message. And jokes. The novel is a massive achievement, but is it magic realism, is it stories or is it a dream?

There is hope here in these stories – the big ones and the little ones in between – but like Norm, you'll need to dive in and almost drown in them to find it. Like Will, the reader is on a quest. Like Truthful the copper, you won't know quite what to believe. And like Elias, you'll emerge from this astonishing novel, sodden but illuminated, and with part of your brain left somewhere in the Dreamtime.