If anyone was going to attempt a properly unhinged allegory of the excesses of modern capitalism and the financial crash, then DBC Pierre was always the man most likely. Not only has he lived the life  his 20s were, by his own account, a decade devoted to disastrous financial punts and druggy self-destruction in his family's Mexican mansion  but he has the Rabelaisian prose style to match. His sentences are toxic assets, often built on wild speculation; his metaphors complex derivatives that you love or hate for their indulgent bravado. From the Booker-winning Vernon God Little on, he has been trading in futures that come into focus every now and then as a skewed and psychotic version of the present.

These sometimes compulsive, sometimes alienating liberties are contained here in the voice of another of his neurotic escapees from the culture, which in Pierre's terms is a "nimbus" of blasted morals and unchecked market forces. Gabriel Brockwell, 25, is in limbo, "firstly because I decided to kill myself. And then because of this idea: I don't have to do it immediately." He is also, when we meet him, in rehab, though not for long. The self-determined gap between life and death is above all a liberation, and his freedom extends to his grip on reality. He is all baroque gesture and paranoid symbolism. His confinement has been brought about by his less than heroic part in an anti-capitalist demo at which he excused himself from the riot by taking out his cash card and letting himself into a bank's lobby. He will end it all, he decides, only after he has organised one final great bacchanal, a bonfire of the bankers, a last supper to end all last suppers.

His plan requires the assistance of his comrade Nelson Smuts, an anarchic chef, a sort of Baader-Meinhof with Michelin aspirations. Smuts is currently resident in Tokyo, where he is dicing with blowfish poison. To raise the funds, Brockwell cleans out his anti-capitalist collective's war chest, fills his pockets with drugs and takes leave of his squat: "an early twenty-first English household  which is to say a tri-sexual household of unparented narcissists where, in the twenty minutes I was there, cash and products were transacted four ways to a sum of four hundred pounds, and no fewer than five laws were broken".

What follows is a sort of addled odyssey fuelled by comic self-aggrandisement and rage against the various machines of money-making. This whirlwind narrative is punctuated with extravagant set pieces, climaxing, literally, in Smuts having violent sex with his teenage stalker in a restaurant fish tank, a scene that acts as a kind of hors d'oeuvres for the decadence that follows.

In the midst of Pierre's soupy plot you either sink or swim, clinging to vivid passing phrases, holding your breath for moments of minor revelation. His writing falls somewhere in a spectrum between William Burroughs and JP Donleavy, a sort of narco-blarney. At its best it captures some of the rigorous circumlocution and comedy of Iain Sinclair in full rant mode, but there are plenty of duff notes and a good deal of baffling rhetorical nonsense. "Euro teens gaggle like piles of socks," he will write.

Arguments occasionally nose into view. The novel's undercurrent is a discussion of whether greed and excess is hardwired into nature, whether humans are born to consume. Brockwell gets his education from the various stooges who assist his efforts to stage his farewell dinner  Didier and Gerd and Gottfried, none of whom emerges quite into the shape of a character. "Capitalism was never a device for societies," one of them explains. "Here's the analogy. Think of a space rocket. Ninety nine per cent of the rocket is just a fuel can  and when the fuel is used up it just falls back to earth. What you see now in the economy is just that  the can falling down empty. The people who built the rocket are way up in space. Nothing will ever touch them or their descendants again, not for five hundred years..."

Brockwell's apocalyptic banquet is designed for exactly those quantum individuals who have lately escaped the tether of the world; and when he has secured Hitler's derelict Tempelhof airport in Berlin for the feast, they fly in from the world's four corners, the accumulators of wealth, the billionaires, the "camel herders and the ruthless bourgeoisie", the "bacteria in suits". Smuts's feast magnifies the fall of Rome, with its hummingbird broth and its panda paw and its white tiger cub with silken tofu and eggplant. Pierre indulges his taste for the satyricon for all he is worth, dogged all the time, apparently, by his knowledge that the revels, like his novel, are ultimately doomed to disturbed and heroic failure.

In a perfect inversion of plain truth, the Royal Bank of Scotland recently assured from billboards that it is "Here For You". In reality the exact contrary is true: We Are Here For It. Capitalism without pesky democracy is our future. If any novelist can collate the killing irony of what is happening around us it is DBC Pierre, who has boiled it down to a culinary emulsion of Hunter S Thompson and Ludwig Bemelmans.

Gabriel Brockwell is an anti-globalisation activist whose daddy never loved him, a booze- and cocaine-partial sybarite in his 20s. His sanctimonious rehab guru, "Spread, creased, and folded by culture into a clever likeness of a man", insists: "Gabriel . . . I don't know whether to treat you or publish you!"

Like Herman Hesse's Harry Haller, from Steppenwolf, Gabriel is liberated from the contradictions raging within by a pledge to commit suicide after one final blowout. Torching his rehab establishment, he flees England with a stash of cocaine and the embezzled funds from an anti-capitalist action group. He heads for Tokyo, where his childhood comrade  Nelson Smuts  works. An implosive neophyte chef  "the epicurian underworld pulled him into its rarest bowel"  Smuts is bound for the blessing of a Michelin star. Smuts's promise has been sponsored by a sinister party organiser and international playboy, Didier Laxalt, "the godfather of high-octane catering".

And it is wine lore that sets up this brilliant satire: Marius is a vine so precious it grows with the assistance of virgins' pheromones and transports the imbiber with visions of its Cote d'Azur slope; the grape is "an ovary inseminated with dreams". It is accompanied by highly toxic blowfish, cut "so thin you could watch porn through it". Gabriel enters a night of gangsters, a teenage girl, a vast fish tank and an octopus. Amazingly, he fails to poison himself in scenes of visionary and comic brilliance.

Smuts believes Gabriel has travelled to Japan not to kill himself, but to invite him to chef in a decadent Berlin nightclub in which Gabriel's father holds a share. However, Smuts is detained in a Tokyo jail on a possible murder charge, giving Gabriel the sudden purpose to free his friend.

The social signifiers of fine wine and exclusive dining have been trumpeted with great solemnity in the last few decades of our culture, but this novel renders it all ridiculous. Pierre shreds the pretentious sophistication and fake joyousness of our Michelin-starred palaces, driving them to the ultimate conclusions of hedonism with a ferocity worthy of de Sade.

The action moves to a finely portrayed and morally complex Berlin, that shimmering borderline where totalitarian capitalism's unsteady contradictions still appear everywhere. Gabriel stakes out Gerd Specht  his father's erstwhile partner  but, hilariously, the mythical nightclub turns out to be much less than envisioned.

Here the novel blossoms into a sort of insane, rococo wedding planner for a tumultuous and orgiastic banquet in the bowels of Nazi-built Tempelhof airport  all organised by Gabriel and Laxalt; they will cater for bankers whose Lear jets taxi to the very gates of Tempelhof and into a double bluff.

Lights Out in Wonderland is an allegory and admits "the improbability of the scheme", but Gabriel is not given over to hedonism; he is a suffering penitent, "Ebenezer Scrooge on a moral tour of Culture Present", and it is the fluency and symphony of fine writing which convince, his waking with daily remorse to one's "mental jury, that tribunal to which we plead and present our mitigations". As with the dextrous ventriloquism in Vernon God Little, Gabriel's living and very beautiful voice carries this convulsive novel: a girl's "buttocks locomote in denim"; a Burger King sign becomes "a delicate graduation of reds from hot capsicum to dry blood"; high intoxication itself is "a glycerine Tibet where you whirl under stars, arms outstretched, free of yourself".

And lurking in such a brazen tale, who would expect such penetrating and subtle Frankfurt School analysis: "Consuming went from being a privilege, to a right, to a duty . . . The fantasy theatre of the markets became our vernacular, till governors themselves pressed ever more spectacular fictions into their service . . . all the evil terrorist men couldn't frighten us together again." Didier Laxalt depressingly confirms that "Capitalism was never a device for societies, it is a rocket, the people who built the rocket are way up in space. Nothing will ever touch them or their descendents for five hundred years."

The wild plot teeters as it ascends to its Grand Guignol climax  a little too in love with the decadence and grand hotels it ultimately condemns, but the point is that decadence itself is not our problem so much as the fact that we can never all practise it. Only the people in that rocket can feast on Caramelised, Milk-Fed White Tiger Cub and Giant Panda Paw with Borlotti Bean & Baby Root Vegetables. Such a culinary obscenity  not so very unrealistic  becomes an exclusive signifier of social superiority. This swollen, bruising novel needs to be defended as an artful shout of protest from a soul on fire, an ultimate call to sanity and to learn what has happened in our world, where "Profit won the game, but like an infection killed the host."

Alan Warner's Booker-longlisted The Stars in the Bright Sky is published by Cape.