In New York, the author meets a strange character, a gemstone expert or perhaps a magician, who convinces him to go to a French village, where he will find an emerald that will reveal his future.
The author is persuaded, partly intrigued by what this strange character tells him, partly because he hopes to track down an old flame, Mariolina, and present himself with a jewel of great value.
Arriving in the French village, he takes lodging in an old hotel, where he falls asleep and seems to enter a strange dream.
He sees the village where he lives, Tellaro, near La Spezia, vastly different from what he remembers, and he no longer recognizes the people:

it is as if they were all new: others.
And it is as if I myself were someone else

.
In the dream he is actually a painter named Andrea Tellarini, living in an isolated house with a dog.
A visitor brings him word that in a French village (the very one where he is actually staying), he has received an inheritance and must therefore go there.
He becomes increasingly aware that he lives in an uncanny world, where, following the Third World War, the globe is divided into two confederations: that of the North, dominated by the Russians, technological and technocratic, and that of the South, dominated by the Arabs and the Chinese, Levantine and agrarian.
Both confederations are dictatorships, two police states dominated by military forces and the secret services.
Between the two confederations runs a Line, roughly traversing Southern Tuscany and Rome, which cannot be crossed because it is contaminated and therefore lethal.
The painter lives in the North within a dictatorial state, where everyone is on the state payroll, travel is forbidden, and cinema no longer exists.
He obtains permission to go to the French village, where he inherits a large emerald, which he resolves to use in order to search for Mariolina.
She, however, lives in the South, and so he must cross the Line.
He sets out on the journey together with his son (in the dream, he discovered he had a son).
The Line is no longer contaminated, and in Rome he encounters some gypsies who salvage treasures from the abandoned city and sell them to a truck driver (in reality, a spy), who transports them South, to Naples.
The painter manages to reach Naples with the truck driver, with whom he is enticed into a homosexual encounter.
In Naples, he meets Mariolina again, but also discovers that the emerald is fake.
His scheme of growing rich and winning back Mariolina has failed; instead, he is dragged into a power struggle between Mariolina's allies and her enemies, for whom the truck driver is a spy.
Mariolina herself proves to be an avaricious woman, thirsting for power.
Captured by Mariolina's enemies, he is brought to Rome and gets caught in a firefight with the gypsies: the dream breaks off abruptly as his wife, summoned by the innkeeper, wakes him.
In fact, he had allegedly not been sleeping and dreaming, but had been writing the dream down for fifteen days without sleep and without food.
It is a fantastic novel, built entirely around the device of the dream as an occasion for an unleashing of nightmares, desires, and fears regarding the future.

I was constructing this dream, complicating it, entangling it, splitting it: a captious, adventurous, fantastic, faerie dream: I was dreaming this dream solely to touch a fragment of my petty reality, of my little self.
Who knows, perhaps it was not even a dream: but a delirium fraught with insurmountable and agonizing contradictions

.
The dream was, in any case, the discovery of a boiling life.

In my dream of discovery I did not wish to go any further.
Better to stop here, I told myself.
Better to wake in time and sleep again, afterwards, dreamless or with bland dreams that are forgotten and not worth remembering

.
Several themes run through the novel: a cruel future, dominated by military or bandit dictatorships: technology has ultimately led to the destruction of the Western political system and its collapse into states lacking the rule of law.
This upheaval may herald the beginning of a new renaissance, precisely because it has destroyed a culture that was already decaying.
In this regard, the reflections on cinema are illuminating.

All that layering of techniques, that paste, that elaborate concoction of acting, dance, drama, scenography, lights, colors, moans: that colossal manneristic, advertising, vulgarly scientific swindle has revealed itself today as a typical—indeed emblematic and exclusive—product of the defunct industrial and consumerist society

If there is any hope of peace and brotherhood with the South, that hope lies in our reborn and unwitting sense of art

; the recovery of a primitive and simple world, namely that of the gypsies.
It is no coincidence that they inhabit a Rome that is ghostly yet alive.

I stopped on the edge and looked all around, near and far, at other valleys and other hills; I contemplated, frightened and fascinated, those horrible alps with their riddled walls, that strange nature, and that matter... They were shells of old mollusks, empty eye-sockets of skulls from which the softness, mobility, and intelligence of life had withdrawn forever.
And suddenly I understood.
They were the hollows where the desire for life entered and from which life itself emerged: dead, however, now, dead; material images of a final sarcasm

.
In a D'Annunzian style, the author reflects upon the transformation of life, finding in nature's destruction of the city, in its abandonment, the starting points for rebirth.
Yet it is not society that will revive it, but that of simple men, of a people—the gypsies—who have rejected industrial and consumerist society; the diverse dimensions of life.
In reality, the author is inhabiting another dimension—not so much what he would have wished to be, but the reality and the persona he could have been.
Does the possibility of another life exist? Are there other worlds within us, where nightmares but also aspirations might be realized? The author's dream is the construction of that other world, of the other life the author could have lived.
The dream broke off precisely

so as to see no more, so as not to know what lay at the bottom of my whole story

.
For Paolo Pasolini, Soldati's writing

is devoid of all viscosity, which is to say, of clinging to the reader, of possessing him, of exerting an unacknowledged authority over him

.
Pasolini speaks of lightness and a relentless reference to something else, to an alternative.
The dream device allows the author to play without explaining: for example, what did the emerald signify? What purpose did the entire affair serve in relation to the opening of the tale? As his friend Enzo Giachino wrote in a letter to Soldati,

I am convinced that a more cultured and subtle reader would be able to unravel the hidden meaning of so many episodes, which eludes me

The Emerald