It is two hours before daybreak, and Noah is sleeping off his earlier activities. Fagin sits up, seething with diabolical rage at what he has learned. Sikes comes in and offers the loot from his past night's work. Even he is frightened by Fagin's maniacal appearance.
When he is able to command his voice, Fagin announces that he has some serious matters to discuss. First he asks Sikes to suppose that the sleeping Noah, in possession of all the gang's dark secrets and under no duress, were deliberately to expose them. Sikes's reaction is that he would brutalize the traitor.
Then Fagin further works at Sikes's temper by supposing someone in their group had committed the dastardly transgression; omitting one, the fiendish schemer names the members of their fraternity — even himself. When he has worked Sikes to a high pitch of suspense and animation, Fagin concludes dramatically: "He's tired — tired with watching for her so long, — watching for her, Bill." And he awakens Noah.
Fagin demands that the drowsy youth relate his account of Nancy's secret dealings. But in a blaze of fury, the old man does most of the talking, shouting out the incriminating facts for Noah's confirmation. When Noah reveals that Nancy drugged Sikes in order to see Rose the first time, Sikes rushes for the door but is unable to get it open immediately. Fagin recovers some of his remarkable self-possession and pleads with Sikes to be "not too violent for safety." Fagin unlocks the door and the avenger dashes out into the morning twilight.
Without hesitation, Sikes charges home and quietly enters his room. He double-locks and barricades the door. Nancy awakens and is pleased to see her man back. When she detects that something is amiss, he drags her into the middle of the room and tells her: "You were watched to-night, every word you said was heard."
The horrified girl struggles fiercely, begging to be spared, just as she spared Sikes. In her wild pleas, she promises to speak to Brownlow so that they can each seek a new life alone in distant places. In her moment of extremity, Nancy uses Rose's mantra: "It is never too late to repent." But Nancy's efforts are in vain. Sikes hits her with his pistol, knocking her down. The bleeding Nancy struggles to her knees and — holding Rose Maylie's handkerchief — raises her hands, pleading with Sikes. Shielding his eyes from the damage he's done to Nancy, Sikes takes up a club and delivers the final blow.
As the life of the city is renewed by the bright sunlight of a fresh day, Sikes sits immovable in the chamber of death. At a sign of life he had followed his first blows with many more. Now he recoils from the sight of his handiwork. Covering the body does not help; and he cannot turn his back to it. He burns the lethal weapon and removes the bloodstains from his clothing. At last, he backs out of the door, locks it, and leaves the house with his dog.
Sikes retreats to the country north of London. All day long, he wanders about aimlessly without plan or purpose. Eventually, he ventures into the village of Hatfield and slinks into a small pub for a meal. The gossip of the local patrons is disrupted by the entrance of "an antic fellow, half pedlar and half mountebank." This vendor is pitching the virtues of a preparation warranted to remove any kind of stain. As the fellow reaches "blood-stains" in his spiel, he snatches Sikes's hat to use for a practical demonstration, because Sikes's hat has spatters of Nancy's blood on it. "With a hideous imprecation [insult]," Sikes recovers his hat and bolts from the premises.
At the post office, Sikes loiters around the stagecoach from London and overhears some talk about a murder in Spitalfields, but the chatter is broken off when the coach leaves. Now Sikes turns toward St. Albans. Alone on the gloomy road, he is tortured by a vision of Nancy that is always behind him and that he cannot in any way shake off. Tormented by mounting terror, Sikes forces himself to enter a dark shed to sleep. But now he is haunted by a vision of the "widely staring eyes, so lustreless and so glassy," of his victim.
Through the blustery night come the sounds of distant cries. Sikes runs in the direction of the voices. A great fire is in progress. Miserable and racked by guilt for having killed Nancy, Sikes welcomes the opportunity for distraction and human company. He works furiously all through the night, with reckless disregard for his own safety, helping to combat the fire.
After the relief of having something to distract him, the agonies of his conscience resume with renewed force. As he shares some food with the firefighters, he hears that he is being sought in the countryside. At that, Sikes decides that his best chance is to return to London, extort some money from Fagin, and try to make his way to France.
Sikes realizes he could be given away by his dog because descriptions circulated are likely to mention the animal. Sikes, therefore, decides to drown his companion and ties a heavy stone in his handkerchief. The mongrel seems to have sensed peril, as he comes to his master unwillingly. When Sikes tries to put the noose around his pet's neck, the beast jumps back and runs off. After waiting some time for the dog to return, Sikes goes on by himself.
The spark of compassion that still warms Nancy's heart sets off a confrontation in which she loses her life. Neither Fagin nor Sikes can be said to have anything resembling ethical standards, and no allowances are made for Nancy's gestures in favor of the two criminals. There is no way to pardon her violation of their merciless code. Fagin applies his twisted intelligence with uncanny shrewdness in showing Sikes how Nancy has betrayed them. He knows with whom he is dealing and how to insure the results he wants.
The aggravation and unleashing of Sikes's ferocious wrath produce a suspense that can only be dissipated by a terrible calamity. The vindictive murder of Nancy is the inevitable result. Her last moments are rendered with crushing pathos. There is rueful irony in her futile belated appeal to the power of repentance. She is even denied a last glimpse of the sun that she so seldom enjoyed. An excruciating contrast is beheld between the restorative light of the dawn and the curtained apartment where Nancy's life is snuffed out.
The sensations of Sikes after the atrocity trace the reactions of a homicide. For the first few hours, he wanders in a kind of daze, scarcely able to relate to what he has done. It is only when the return of darkness vividly recalls the deed that he feels the full implications of his position: "Let no man talk of murderers escaping justice, and hint that Providence must sleep." Awareness of guilt and the sense of danger become overwhelming. The horror of his stigma isolates him from his fellow men. The harshness of this penalty is eloquently demonstrated by Sikes's eagerness to lend his assistance during the emergency of the fire, just so he can be near other people and find momentary forgetfulness in hard physical labor. It is an unprecedented spectacle for others to receive help from Sikes, an enemy of society who has never shown anything but contempt for all humanity.
At the end of Chapter 48, Sikes is left in an ironical position: After impetuously slaying the one person who had affection for him, he is unsuccessful in a deliberate attempt to destroy his dog, whom he fears may be a threat to his own existence.