The novel is set in the Underdark, a vast subterranean world of lightless tunnels and caverns beneath the surface of the Forgotten Realms. Deep within lies Menzoberranzan, a city of 20,000 drow (dark elves) whose elegant, magically illuminated architecture masks a society driven by treachery, ambition, and devotion to Lolth, the Spider Queen, their cruel deity. Drow society is rigidly matriarchal: Noble houses are ruled by matron mothers who serve as high priestesses, and a house's rank rises or falls through covert warfare, with the annihilation of rival families tolerated so long as no witnesses survive.
The story begins on the night House Do'Urden, the city's 10th-ranked noble house, launches a coordinated assault on House DeVir, the fourth-ranked house, whose matron has fallen out of Lolth's favor. Dinin Do'Urden, Malice's son, leads soldiers and expendable goblin slaves to breach House DeVir's defenses. Matron Malice Do'Urden, heavily pregnant, channels the agony of childbirth into a devastating spell that shatters DeVir's chapel. Zaknafein, the house's weapons master and the city's finest swordsman, infiltrates alone and kills every DeVir cleric. As the battle concludes, Malice's eldest daughter, Briza, prepares to sacrifice the newborn to Lolth, as custom demands the death of a third-born male. Malice names the child Drizzt. Before the sacrifice proceeds, Dinin murders his older brother Nalfein by stabbing him in the back, seizing the title of elderboy, the rank of the house's eldest male heir. Because Nalfein's death fulfills the sacrificial requirement, Drizzt is spared.
At Sorcere, the Academy's school of wizardry, a young apprentice of House Hun'ett named Masoj Hun'ett kills a disfigured master of Sorcere known as the Faceless One, who had been assigned to assassinate the sole surviving DeVir noble, Alton DeVir. Masoj and Alton strike a deal: Alton assumes the dead wizard's identity, with Masoj using acid to destroy Alton's remaining facial features to complete the disguise. Alton's sole reason for living becomes revenge against whichever house destroyed his family. Years later, Matron SiNafay Hun'ett, Masoj's mother, discovers the deception and adopts Alton into House Hun'ett, revealing that House Do'Urden destroyed his family. She plans to use Alton's legitimate grievance as pretext for a future war.
Zaknafein, walking through the aftermath of the battle, is horrified by the slaughter of DeVir's children. Alone in a secluded grove, he cries out against the evil of Menzoberranzan, wishing he had the courage to leave or resist.
Drizzt, noted for his unusual violet eyes, spends his early years under strict indoctrination by his sister Vierna, who enforces obedience with a snake-headed whip. The most persistent lesson of his childhood is hatred of the surface elves, whom the drow blame for driving them underground. At 16, Drizzt begins weapons training under Zaknafein, who recognizes the boy's extraordinary dexterity and calls him "Two-hands." Over three years, they develop a deep bond through shared love of combat and mutual moral sensibility. Before Drizzt departs for the Academy, Malice and her daughters, including her youngest daughter Maya, use magical compulsion to force him to kill a helpless creature, testing his willingness to obey. Zak argues against sending Drizzt, warning "they will ruin him," but Malice overrules him. On Drizzt's last day, Zak stages a desperate fight, secretly intending to kill Drizzt mercifully; he uses an enchanted light pellet to blind and disarm him but cannot deliver the blow. Drizzt departs believing Zak is as evil as the rest.
At Melee-Magthere, the Academy's school of fighters, Drizzt endures nine years of training and indoctrination. He dominates the annual grand melee tournaments, his scimitars becoming his only trusted companions. In his ninth year, he discovers that his masters planted a child as bait during a training exercise, and Vierna and Dinin casually reveal that House Do'Urden destroyed House DeVir, that Zaknafein killed the clerics, and that Dinin murdered Nalfein. These revelations shatter Drizzt's remaining faith in his family. During his final year, Drizzt becomes deeply attached to Guenhwyvar, a magical panther summoned from the Astral Plane, an extradimensional realm, via an onyx figurine belonging to Masoj. At Arach-Tinilith, the school of Lolth, Drizzt flees a demonic ritual and denounces the Spider Queen. Vierna retaliates by abandoning him in a cavern inhabited by driders, drow transformed into half-spider abominations for displeasing Lolth. Malice rescues him with a brutal warning.
Drizzt's patrol is then selected for a surface raid against elves. The drow emerge under a moonless sky, and Drizzt is awed by the stars. Dinin leads them to a glade where elves dance and sing around a fire, and the drow attack without warning. During the massacre, a slain elf's young daughter runs toward Drizzt. He raises his scimitar but cannot strike. He fakes the kill, pulling the child down and covering her with her mother's blood. At dawn, while the other drow flee the sunrise in agony, Drizzt stands alone in the growing light, wishing he could place a thousand suns in every chapel in Menzoberranzan.
Back in the city, Dinin boasts that Drizzt hacked the child apart. Zaknafein, listening from the shadows, believes Drizzt has become a heartless killer. SiNafay, learning House Do'Urden has lost Lolth's favor, orders Masoj to kill Drizzt. On a subsequent patrol against svirfnebli (deep gnome) miners, Masoj fires a lightning bolt at Drizzt under cover of battle. Drizzt survives and intervenes to save the gnome leader, Belwar Dissengulp, arguing one gnome should be sent back as a warning. Dinin agrees but orders Belwar's hands cut off. Belwar endures without a scream, locking eyes with Drizzt and recognizing his hidden anguish. After the patrol, a yochlol, a shapeshifting handmaiden of Lolth, warns Malice that someone in the family has displeased the Spider Queen. Drizzt identifies House Hun'ett as their enemy based on Masoj's attempted murder.
Drizzt returns to the training gym, where he and Zaknafein each secretly intend to kill the other. Zak believes Drizzt murdered the elven child; Drizzt believes Zak is a hypocritical killer. They fight with lethal intent. During their earlier training, Drizzt had challenged a standard parry technique, insisting a kick between crossed sword hilts was a viable counter; he now executes the maneuver successfully. Zak recovers and pins Drizzt to the wall with a blade at his throat. Drizzt gasps the truth: The child lives.
Zak leaps back, then embraces Drizzt, weeping. "You have survived! My son!" he cries, admitting for the first time that Drizzt is his biological child. But Malice and Briza have been watching through a scrying bowl, a magical basin for remote observation. They identify Drizzt as the source of Lolth's anger and declare a sacrifice necessary before the coming war with House Hun'ett. Zak offers himself in Drizzt's place. As he is bound to the altar, he whispers a final prayer: "Do more than survive. Live! Be true to the callings in your heart."
Drizzt, who has fled the city, is followed by Masoj, who commands Guenhwyvar to hunt and kill him. The panther finds Drizzt trapped by a cave fisher, a crablike tunnel predator, and the sight of Drizzt in danger breaks through the figurine's magical compulsion. Guenhwyvar saves Drizzt instead. Drizzt then confronts Masoj and Alton DeVir, who reveals his identity and vendetta. In the ensuing battle, Alton's wand explodes and kills him, and Drizzt slays Masoj, recovering the onyx figurine.
Returning to House Do'Urden, Drizzt learns that Zaknafein was sacrificed to Lolth because his mercy toward the elven child angered the Spider Queen. Malice offers him the title of weapons master in exchange for obedience. He refuses. Finding one of Zak's enchanted light pellets in the weapons master's abandoned pouch, Drizzt smashes it on the floor, blinding his entire family. "A true god damn you all! And damn that Spider Queen as well!" he cries, and flees.
Outside the city, Drizzt summons Guenhwyvar from the figurine. The panther materializes, alive and whole. Standing above Menzoberranzan for the last time, Drizzt bids farewell to the city and to his father, declaring that he leaves as Zaknafein could not. He steps into the tunnels of the untamed Underdark with Guenhwyvar at his side.