Chapter I: War Within Four Walls
The first wave of the attack on the barricade recedes, and the defenders fortify the structure. Their food has run out, and Enjolras forbids them from drinking alcohol in order to prevent them from getting drunk.
As the dawn approaches, the revolutionaries chat together, about life, love, and politics. However, Enjolras brings bad news that shatters this calm: a massive force is coming to crush the barricade. To make matters worse, after a few sporadic incidents, the population has not joined the uprising, instead shuttering their doors against the revolutionaries.
The defenders of the barricade are resigned to death, but they do not despair. Enjolras offers the chance for any man who wants to leave the barricades now and return to his family. No one budges.
Still, Enjolras brings out four Gaurde Nationale uniforms, stripped from dead officers. The rebels can dress in these uniforms and slip away from the barricade undetected. Courageously, all of the defenders continue to refuse to desert the barricade. Combeferre points out the selfishness of men with families leaving their wives and children to fend for themselves: widowed wives and daughters may resort to the soul-killing profession of prostitution, and children will endure terrible hunger. He finally singles out five men with dependents. Alas, there are only four uniforms!
As the men are debating what to do, a fifth uniform falls on the pile. Jean Valjean has arrived, and he offers up his Guarde Nationale uniform. The family men successfully leave the barricade, and Valjean is welcomed into the ranks of the defenders. Marius is so distracted with exhaustion and anxiety that he barely notices the arrival of Cosette's father.
Enjolras inspires his men with a rousing speech about the future, which will be characterized by liberty, justice, and equality. The deaths of the defenders of the barricade will hasten the coming of this glorious future.
Suddenly, Enjolras recalls Javert, tied to a pillar. He offers Javert a bit of water; the police officer is unruffled by his perilous situation and his looming death. His calm is only broken when he looks across the room and sees Valjean, who recognizes him as well.
Dawn marks the beginning of a terrible battle. The defenders are far outnumbered by the new force, which has brought a cannon to smash the barricade. Gavroche returns, to the joy of the revolutionaries and the dismay of Marius, who had hoped he had saved his life.
The battle is dramatic and fierce. Even the zealot Enjolras has a moment of doubt when he must shoot a youthful gunner; the man is his spiritual brother, a man of France. Still, Enjolras does his duty for the revolution and kills the man. Valjean, meanwhile, endears himself further to the revolutionaries when he braves a hail of bullets in order to retrieve a mattress that will reinforce the barricade against cannon fire. They respect Valjean so much that they tolerate his peculiar habit of shooting soldiers in the helmet, so that it does not kill them but instead drives them off the battlefield.
In another, quieter part of Paris, Cosette awakes from a dream of Marius. She hopes he will come to see her, but there is no sign of him - not even a letter, which Valjean took. She weeps disconsolately. In the distance is the sound of cannon fire, which mingles with the tweets of the birds that nest by her window.
Meanwhile on the barricade, the situation becomes dire. The revolutionaries are extremely low on bullets, and the army continues to advance. Gavroche decides to remedy the situation by gathering up discarded bullets in the area between the barricade and the army. The soldiers shoot at him, but he dodges the bullets like a little sparrow, singing a rude little song the whole time. However, the bullets finally find their target, and Gavroche dies.
At the same time as Gavroche's heroic death, the two little boys (his blood brothers, whom he rescued) are wandering in the Luxembourg gardens, hungry and penniless. A bourgeois man and his son are also walking the garden, and look at the ragged children with disdain. The young boy, decides he does not want to eat his pasty, so his father advises him to feed it to the swans in the garden, because it is good to show compassion to animals. After the two walk away, one of the little boys fishes the soggy pastry out of the pond and shares it with his brother.
The defenders only have a short time to prepare before the assault begins. Enjolras decides that the time has come to execute the spy Javert; Valjean offers to undertake this task. He leads Javert outside the tavern and away from the other defender, but rather than shooting him, he cuts Javert's bonds with a knife and tells him that he is free to go. Not only that, but Valjean gives Javert (who has spent years hunting him) his name and address. Javert is completely stunned, and makes away into the darkness; Valjean fires the pistol into the air to conceal his act of mercy from the rest of the ABC Society.
The army mounts a great assault on the barricade, driving the revolutionaries to take shelter in the Corinth tavern, despite their bravery. Many are killed, including several members of the ABC Society. Marius collapses from a number of small wounds, but a powerful hand lifts him up.
Enjolras makes a final stand in the corner of the wine shop. His weapons gone, he crosses his arms and faces his attackers serenely; his assailants pause in wonder at his mythic appearance. This unexpected silence has the effect of waking Grantaire, still slumbering off his alcohol in a corner. Grantaire takes in the whole situation, then walks to Enjolras' side. The two clasp hands. "Long live the Republic! Kill two birds with one stone," Grantaire says defiantly to the soldiers. The two friends face the firing squad together, dying bravely. The army routs the rest of the rebels, and the battle ends.
There are two survivors. When Jean Valjean saw Marius collapse from his wounds, he picked up him and carried him off. Valjean escapes the tavern, but he finds himself trapped, with a dead end at the back and the army at the front. Thinking quickly, he notices a an iron grating covering the entrance to the sewer; with his great strength, he lifts it up and takes refuge in the sewer with Marius in tow.
Chapter II: Entrails of the Monster
This chapter is a meditation on the sewer, in Paris and throughout history. Victor Hugo argues that the extensive Paris sewer system (which channels human waste into the sea) is actually a tremendous waste of wealth; sewage makes an excellent fertilizer, and could revitalize crop fields. He goes so far to say that Paris is dumping gold into the ocean.
Sewers are also fascinating from a social perspective. Disgraced aristocrats, criminals, and political prisoners have all sought refuge in the sewers, which constitute a city under the city. Moreover, they are a testament to the brotherhood of humanity: the dress of a duchess molders next to a broken bottle from a wino's drink.
Chapter III: Mire, but the Soul
Jean Valjean, carrying Marius on his back, has little time to ponder such things. Plunged into pitch darkness, he advances bit by bit, seeking an exit that will take him far from the riot above. Though he suffers from hunger and thirst, not to mention terror of this stinking darkness, but he pushes onward.
Suddenly, Valjean detects a faint light in this pitch darkness, far behind him. It is the lantern of a police patrol, scanning the sewers for escaped insurrectionists. Valjean flattens himself against a wall, unsure if he will be captured. The light fades away.
The police are also committed to maintaining order elsewhere. A policeman pursues a thief along the banks of the Seine, trailing him until the criminal disappears into a mass of underbrush by the river. The thief has disappeared into the grate of a sewer, and like a patient hunting dog, the policeman sits down to wait.
Valjean is not free from danger. He pushes on through the sewer, through thick layers of filth that suck at his legs and pull him down. Hours pass. Marius' body becomes an increasingly difficult burden, but Valjean cannot bring himself to abandon this young man who Cosette loves. Valjean also finds a note to Marius' grandfather in the young man's pocket, asking the reader to return his body to his grandfather Gillenormand.
Valjean pushes on through the sewer. Terrifyingly, he feels the pavement disappear under his feet, and he sinks into the filth up to his neck. He is forced to carry Marius above his head. Valjean is sure he will die and turns his thoughts to God - and finds his feet on solid ground.
Not far ahead, Valjean sees a window of light. It is a sewer grating, far from the upheaval of the riot. Valjean's delight quickly turns to horror when he realizes the grate is locked. With despair and frustration, Valjean realizes that he may have made this long, difficult journey only to die alone in the darkness.
Valjean feels a hand on his shoulder. It is a thief, whom he recognizes as Thénadier. "Share and share alike," the criminal says as he produces a master key that can unlock all sewer grates in Paris. Assuming that Valjean is a murderer and Marius his victim, Thénardier demands half of the man's money. Valjean gives him the 30 francs he has in his pocket, and Thénardier accepts this with some disappointment; however, Thénardier takes advantage of Valjean's momentary distraction to rip off a piece of his garment, thinking it may be useful to identify the man later.
The sewer swings open, and Valjean is free. Thénardier disappears into the twilight, but Valjean lays on the bank for a moment with the limp form of Marius beside him, experiencing a deep joy.
Suddenly, he sees a form nearby. It is Javert, pursuing him to the last. Thénardier let Valjean out of the sewer in order to provide a distraction to Javert and escape freely. Valjean does not resist arrest, but merely asks to be allowed to bring Marius back to his grandfather. Recalling the mercy Valjean showed to him on the barricade, Javert agrees, even paying for a carriage to transport them there.
They arrive at the Gillenormand residence at dusk, and Valjean brings Marius upstairs. Everyone is asleep, but the servants rouse themselves to find a horrible sight: the bloody, motionless body of Marius. The servants prepare a camp bed and call the doctor; the doctor is not optimistic about Marius' chances for survival.
Gillenormand himself is woken by the commotion, and upon the sight of Marius, is overcome with grief and despair. He is distraught at the death of his grandson, and grieved that they were estranged when this awful thing happened. He reminisces about Marius as a baby, and laments that Marius will be buried before him. Suddenly, Marius opens his eyes, and Gillenormand faints dead away from shock.
Valjean has left unobtrusively, Javert with him. Valjean softly asks for one more favor: he wants to stop at the house on the Rue de l"Homme Armé and say goodbye to Cosette. Javert grants this wish.
To Valjean's amazement, Javert allows him to go into the house and see Cosette alone. Valjean pauses for a moment on the landing, already full of sorrow at seeing Cosette this one last time. He looks out the window, and sees only a deserted street. Javert is gone.
Chapter IV: Javert in Disarray
For the first time in Javert's life, he is caught in a turmoil of indecision and doubt. He wanders a parapet along the Seine, his mind whirling. For the first time in his life, he has betrayed his duties as a police officer by letting Valjean go; however, Valjean also spared his life at the barricade, and this act of kindness must be repaid. Javert had lived all his life ruled by strict rules, but now cracks appear in his mental armor. A criminal has acted righteously. A policeman has broken the law, by aiding and abetting a fugitive. Perhaps judicial law is not the highest law of the land. Javert cannot solve all of these terrible paradoxes.
Numb, Javert finally understands what he must do. He returns to the police station at the Seine, and makes a number of suggestions for improving the lives of prisoners and the rules of police administration; for example, prisoners awaiting trial are forced to sit on the ground in their bare feet, and Javert suggests that they be allowed to keep their shoes.
Javert then returns to the Seine parapet. The water swirls in the dark, and the night is silent until it is broken by a splash. Javert has killed himself.
Chapter I, describing the assault upon the barricades, contains frequent allusions to the battle of Thermopylae. This was an ancient battle between a small Greek force and the massive Persian army, which took place at a narrow pass. The Greeks knew they faced certain death, but conducted themselves with courage on the battlefield and won the rest of the Greek forces enough time to eventually drive off the much larger Persian army. The battle is often invoked to symbolize laying down one's life for one's ideals, an idea that resonates among the members of the ABC Society.
After Gavroche's death, the narrative moves to focus on the two little boys he once cared for, the blood brothers whose identity he never knew. They are struggling but surviving, stealing crumbs from the bourgeoisie to get by. The image of the little boys fishing out the pastry from the swan pond illustrates the ugly charity of treating animals better than one treats one's fellow humans. It highlights the hypocrisy of offering a pastry to a swan, and treating two children as a nuisance.
Chapter II (the meditation on the sewer) contains what some critics call Hugo's only useful policy recommendation: diverting the waste of Paris to fertilize the fields of France. Always quick to find the poetry and symbolize in even the most common place things, Hugo also describes the sewers as a place where all the waste of every person - from kings to peasants - molders.
Valjean's harrowing journey through the sewers evokes images from classic myth and literature: Inanna or Persephone in the underworld, Dante's journey through hell. Having overcome so much darkness, he must face one last trial and overcome the greatest darkness.
However, his greatest adversary is waiting for him on the other side of the sewer grate. As soon as he was released by Valjean at the barricade, Javert immediately returned to his duties, and happened to find Valjean by the banks of the Seine. The two are faced with a similar situation to that in Monfermeil so many years ago: Javert has apprehended his ex-convict, and Valjean begs for a stay of his sentence until he can administer one final act of charity. This time, however, Javert allows him to do complete his work (and in fact, allows him free entirely). This emphasized the importance of second chances in the narrative - in order to grow, characters must be able to fix the mistakes that were made the first time.
Javert makes the more ethical choice this time, but he is plunged into mental chaos. Faced with the possibility that everything he has lived his life for is wrong, Javert commits suicide.
Unlike Valjean, who was faced with the same revelation at the beginning of the book and embarks on an arduous but rewarding spiritual journey, Javert is too rigid to ever give up his strict ideas.
The conflict between Javert and Valjean mirrors the conflict between justice and charity. Charity is not just; it advocates the absence of punishment even in cases of terrible wrongdoing, and it recommends love over vengeance. After meeting Myriel, Valjean gave his life over to charity. However, Javert cannot go against his nature, and he ends his life after his great act of charity.