The Son of Neptune

Name: The Son of Neptune (The Heroes of Olympus, #2)
Author: Rick Riordan

by Rick Riordan

Genre

Fantasy, Young Adult, Children's

Year

2011

Pages

196

Contents

Overview

The Son of Neptune follows Percy Jackson after he awakens with almost no memory, hunted by monsters and guided toward a hidden Roman demigod stronghold called Camp Jupiter. There he meets Hazel Levesque, a daughter of Pluto burdened by a mysterious past, and Frank Zhang, an uncertain recruit whose family secrets make him more powerful and vulnerable than he realizes.

The camp faces a growing threat from Gaea, who is reviving monsters and preparing armies while Death itself has been chained. Percy, Hazel, and Frank are sent north on a dangerous quest that may save Camp Jupiter, restore lost honor, and reveal how Greek and Roman demigods fit into a much larger war. The story centers on identity, loyalty, sacrifice, second chances, and the challenge of trusting allies across old divisions.

Plot Summary ⚠️ Spoilers

Percy Jackson arrives near Berkeley exhausted, filthy, and nearly without memory, pursued by the immortal Gorgon sisters Stheno and Euryale. He remembers only flashes, especially a girl named Annabeth, and relies on instincts learned from Lupa, the wolf who trained him. The Gorgons reveal that Gaea is reviving monsters and that Percy carries the mark of Achilles, but he escapes downhill and reaches a hidden entrance to Camp Jupiter. There an old woman named June asks him to choose between safety at sea and carrying her into camp. Percy chooses the harder path. Crossing the Little Tiber strips away his Achilles invulnerability, but he uses the river to destroy the Gorgons and protect Frank Zhang. June reveals herself as Juno and presents Percy as a son of Neptune.

Camp Jupiter receives Percy warily. Reyna, the camp’s praetor, questions him, while Hazel Levesque and Frank help him understand Roman customs, the five cohorts, New Rome, and the camp’s fear that monsters are becoming harder to kill. Percy is sent to Octavian, the ambitious augur, whose ritual approves him for the legion but also reveals his political hostility. Hazel sponsors Percy into the disgraced Fifth Cohort, accepting responsibility for his conduct. Percy learns that the Fifth has long suffered from the loss of the legion’s golden eagle during a failed Alaska expedition, and that the Feast of Fortuna is only days away.

Hazel and Frank each carry dangerous secrets. Hazel was born decades earlier in New Orleans, where her cursed power over precious metals brought misery and made her vulnerable to Gaea’s manipulation of her mother, Marie Levesque. In Alaska, Hazel was forced to raise the giant Alcyoneus, but she collapsed his island and died with her mother, delaying his rise. Nico di Angelo later brought Hazel back from the Underworld, where she had accepted Asphodel rather than abandon her mother to punishment. Frank, meanwhile, learns that his life is tied to a charred piece of wood: when it burns completely, he will die. He is revealed as a son of Mars and heir to an ancestral shapeshifting gift.

During war games, Frank devises a plan that lets Hazel, Percy, and him flank the fort through tunnels. Percy destroys the water cannons, Frank creates a rope ladder with a hydra arrow, and the Fifth Cohort wins. Celebration ends when Gwen is murdered and then returns to life, proving Death’s hold has weakened. Mars appears, reveals that Thanatos has been chained and the Doors of Death are open, and names Frank his son. He orders a quest to Alaska to free Thanatos by June 24, with Percy required as one companion and Hazel chosen as the third.

The senate confirms the quest but grants little aid. Nico explains that Alcyoneus is Pluto’s opposing giant and is immortal in his home territory of Alaska. Reyna privately asks Percy to find her sister Hylla near Seattle, gives him Bellona’s ring, and warns that a giant-led army is marching toward Camp Jupiter. Percy, Hazel, and Frank set out in a battered boat called Pax, guided by Percy’s sea powers, while Gaea taunts Percy as a pawn.

The quest north forces the three to rely on one another. They encounter karpoi, witness Polybotes leading a monster army south, and take refuge in a store run by Iris. Iris heals Percy’s memory sickness and sends them to Portland to consult Phineas, a cruel seer revived by Gaea. Phineas torments harpies and demands the capture of the red-feathered harpy Ella in exchange for information. Instead, the heroes befriend Ella, discover her perfect memory and prophetic knowledge, and trap Phineas in a wager using two vials of Gorgon’s blood. Gaea preserves Percy because she still needs him, and Phineas dies by choosing the poisonous vial. The heroes gain the location: Hubbard Glacier.

In Seattle, the group seeks Hylla among the Amazons. Hylla, now queen, recognizes Percy from the destruction of Circe’s Island but listens because of Reyna’s ring. Her rule is threatened by Otrera, the resurrected Amazon founder allied with Gaea. Unable to openly help, Hylla secretly enables Hazel to free Percy and Frank, recover their gear, and release Arion, a fierce immortal horse who accepts Hazel after she feeds him gold. Hazel leads a breakout through the Amazon warehouse, and Arion carries them north at impossible speed.

In Vancouver, Frank returns to his family home, which is besieged by Laistrygonian giants. Mars tells him Gaea wants him dead and that he is one of the Seven. Frank’s grandmother explains his shapeshifting inheritance and arranges their escape by plane, while the house burns under attack. Ella refuses to fly, so Percy contacts Tyson and Mrs. O’Leary in a dream, asking them to protect her and bring her to Camp Jupiter. Percy also remembers Camp Half-Blood and realizes Juno has exchanged him and Jason Grace to begin uniting Greek and Roman demigods.

In Alaska, the heroes survive attacks by Stymphalian birds, gryphons, wilderness, and Gaea’s attempt to drown Percy and tempt Hazel with an illusion of a restored life. Hazel revisits her old Seward home, where Percy recognizes a photo of Sammy, deepening questions around Hazel’s past. Arion carries them across the sea and up Hubbard Glacier, where they find a frozen imitation of Camp Jupiter, the chained Thanatos, Roman shades, and Alcyoneus. Thanatos says his chains can be melted only by the fire of life. Frank accepts the cost and uses his life-tied wood to free Death, while Percy seizes the lost eagle and draws away the shades.

Thanatos declares that deaths will now hold but refuses to fight. Frank discovers his shapeshifting power, becoming an eagle and a bear to battle Alcyoneus, then helps Hazel and Arion drag the giant out of Alaska into Canada, where his immortality fails. Frank becomes an elephant to weaken him, and Hazel beheads Alcyoneus, ending the giant she once raised. They return to find Percy alive with the eagle and salvage Imperial gold weapons and a chariot from the bay. Arion races them south to Camp Jupiter, where Polybotes’s army is already attacking.

Percy’s memories fully return as the battle begins. Tyson, Ella, and Mrs. O’Leary arrive, and the heroes deliver the eagle and recovered weapons to the legion. The Fifth Cohort rallies, the eagle’s lightning turns the tide, and Hylla’s Amazons arrive to flank the monsters after defeating Otrera. Percy lures Polybotes across New Rome’s boundary and, with the outraged boundary god Terminus, kills the giant. Camp Jupiter celebrates victory at the Feast of Fortuna; Hazel and Frank are honored, and Percy is made praetor. In a dream, Juno tells Percy the next task is to unite the camps, sail to the ancient lands, and close the Doors of Death. At dawn, Leo Valdez sends word that the Argo II is arriving under truce. Octavian urges attack, but Percy swears the Greeks are allies, Reyna supports him, and the Romans prepare to meet Percy’s other family.

Characters

Percy Jackson

An amnesiac son of Neptune who arrives at Camp Jupiter after being hunted by Gorgons. His powers over water, loyalty to friends, and recovered Greek identity make him central to the quest to free Thanatos and to the fragile alliance between Roman and Greek demigods.
Hazel Levesque

A daughter of Pluto from 1941 whose cursed control over precious metals once helped Gaea raise Alcyoneus. Resurrected by Nico, she seeks redemption by joining the Alaska quest, mastering Arion, and ultimately confronting the giant tied to her past.
Frank Zhang

A son of Mars whose life is bound to a fragile piece of firewood and whose family carries a shapeshifting gift. He grows from an insecure probatio into a centurion, frees Thanatos at personal risk, and becomes one of the quest’s decisive heroes.
Reyna Avila Ramírez-Arellano

The praetor of Camp Jupiter who tests Percy’s loyalty, manages the camp’s political tensions, and entrusts him with a request to find her sister Hylla. Her decision to back Percy’s call for peace with the Greeks is crucial to the ending.
Octavian

Camp Jupiter’s augur and a legacy of Apollo who uses omens, fear, and politics to gain influence. He repeatedly mistrusts Percy and the Greeks, limiting aid for the quest and urging attack when the Argo II arrives.
Nico di Angelo

Hazel’s brother and a son of Pluto who brought Hazel back from the Underworld. He hides his prior connection to Percy, explains the threat of Gaea, giants, Thanatos, and the Doors of Death, and later becomes a missing piece in the larger quest.
Juno

The goddess who brings Percy to Camp Jupiter, first disguised as June, and reveals him as Neptune’s son. Her plan exchanges Percy and Jason to force Roman and Greek demigods toward unity against Gaea.
Gaea

The earth goddess and primary antagonist working to awaken fully, revive monsters, and use the opened Doors of Death to overwhelm the demigod camps. She manipulates Hazel’s past, taunts Percy through dreams, and coordinates the giants’ war.
Mars

The Roman god of war who claims Frank as his son and orders the quest to Alaska. His harsh lessons about duty, sacrifice, and ancestral power shape Frank’s growth.
Thanatos

The god of Death, chained at Hubbard Glacier by Alcyoneus’s forces. His imprisonment allows monsters and some mortals to return, and freeing him restores the permanence of death.
Alcyoneus

The eldest giant and Pluto’s foe, raised through Hazel’s cursed powers and immortal while in Alaska. He holds Thanatos and the legion’s lost eagle until Hazel and Frank drag him beyond his homeland and defeat him.
Polybotes

The giant born to oppose Neptune, commander of the army marching on Camp Jupiter. He seeks Percy for a ritual death but is killed when Percy works with Terminus at New Rome’s boundary.
Queen Hylla

Reyna’s sister and queen of the Amazons, living with resentment toward Percy from their shared past at Circe’s Island. Despite a coup attempt by Otrera, she secretly aids Hazel’s escape and later brings the Amazons to help Camp Jupiter.
Otrera

The resurrected founder of the Amazons who allies with Gaea and challenges Hylla’s rule. Her coup forces Hylla to conceal her support for the heroes.
Ella

A red-feathered harpy with perfect recall, including fragments of prophetic texts. Percy, Hazel, and Frank rescue her from Phineas, and her knowledge becomes important enough that the heroes must protect her from Octavian.
Tyson

Percy’s Cyclops brother who searches for him with Mrs. O’Leary. He protects Ella, comes to Camp Jupiter, and fights beside Percy during the final battle.
Arion

An immortal, gold-eating stallion who accepts Hazel as his rider. His impossible speed lets the questers escape the Amazons, reach Hubbard Glacier, and return to Camp Jupiter in time.
Terminus

The god of boundaries who enforces New Rome’s rules and the Pomerian Line. His rigid concern for regulations becomes decisive when Percy persuades him to help kill Polybotes.
Iris

The rainbow goddess who runs a nonviolent organic shop and shelters the heroes from Polybotes’s forces. She heals Percy’s memory sickness, advises Frank, and directs the group to Phineas.
Phineas

A blind seer revived by Gaea who abuses the harpies bound to his food. Percy defeats him through a Gorgon’s-blood wager, winning the location of Alcyoneus’s lair.
Marie Levesque

Hazel’s mother, also called Queen Marie, whose wish for Pluto’s riches contributed to Hazel’s curse. Under Gaea’s influence she takes Hazel to Alaska, but she regains her will before dying with Hazel.
Pluto

Hazel’s father, who warns Marie not to go to Alaska and foretells that a descendant of Neptune may one day wash away Hazel’s curse. His realm and judgment shape Hazel’s second chance.
Frank’s grandmother

The stern Zhang family matriarch who reveals Frank’s divine parentage, his life-bound firewood, and his family’s shapeshifting inheritance. She arranges the escape from Vancouver and sends Frank onward toward Alaska.
Emily Zhang

Frank’s mother, a Canadian army captain whose death in Afghanistan leaves Frank grieving when he comes to Camp Jupiter. Her stories about family heritage and sacrifice influence Frank’s understanding of his powers.
Sammy

Hazel’s friend and crush from 1941 New Orleans. His memory represents the life Hazel lost, and Percy’s recognition of his photo connects Hazel emotionally to later events.
Annabeth Chase

The girl Percy remembers even through his amnesia and the person he is determined to find again. Her search for Percy and Juno’s warning about her future task frame Percy’s hopes beyond the Alaska quest.
Jason Grace

The missing son of Jupiter and former praetor whose disappearance leaves Camp Jupiter unsettled. Percy realizes Juno likely exchanged him and Jason to begin uniting the Roman and Greek camps.
Leo Valdez

The builder associated with the approaching Argo II who sends a message announcing the Greek ship’s arrival under truce. His resemblance to Sammy shocks Hazel.
Lupa

The she-wolf who trained Percy and Frank before they reached Camp Jupiter. Her absence during the final attack signals that the legion must prove itself without wolf support.
Stheno

One of the Gorgon sisters who hunts Percy at the beginning and later appears among Polybotes’s forces. Her repeated regeneration demonstrates the danger caused by Death’s imprisonment.
Euryale

The more vengeful Gorgon sister pursuing Percy for Medusa. She helps reveal Gaea’s patronage of monsters before Percy destroys the sisters in the Tiber.
Dakota

A Fifth Cohort centurion and son of Bacchus who helps represent the cohort’s disreputable but loyal character. He bears the restored eagle in the final battle and helps channel its lightning.
Gwen

A Fifth Cohort centurion whose murder and immediate revival prove that Death’s power has failed. Her retirement opens the centurion role that Frank fills.
Vitellius

The eccentric Lar of the Fifth Cohort who comments on legion history and the cohort’s decline. He helps expose details about Frank’s gorgon-blood vials and family curse.
Kinzie

An Amazon loyal to Hylla who captures the heroes in Seattle but helps position Hazel for the planned prison break. She later appears among the Amazons allied with Rome.
Ma Gasket

A Cyclops matriarch in Polybotes’s army who vows vengeance on demigods connected to the Greek camp. She appears during the siege of Camp Jupiter and is defeated by Tyson.
Mrs. O’Leary

Percy’s massive hellhound who travels with Tyson while searching for Percy. She helps bring Tyson and Ella to Camp Jupiter and pulls the chariot during the counterattack.
Hannibal

Camp Jupiter’s armored elephant used in war games and camp transport. He helps the Fifth Cohort break through during the games and symbolizes the camp’s unusual Roman military style.
Don

A faun at Camp Jupiter who repeatedly begs around the camp and appears during the celebrations. He also notices Percy’s suppressed empathy link, briefly hinting at connections Percy cannot yet remember.

Themes

Rick Riordan’s The Son of Neptune is a story about broken identities being rebuilt through trust, sacrifice, and chosen allegiance. Though it moves with the speed of a quest adventure, its deeper force comes from characters who must decide who they are when memory, history, and even death itself have become unstable.

Identity beyond memory and origin. Percy arrives at Camp Jupiter stripped of nearly everything except instincts, loyalty, and the name Annabeth. His Greek sword, the Lares calling him Graecus, and Reyna’s suspicions all mark him as an outsider, yet he earns Roman trust through action. Hazel and Frank mirror this uncertainty: Hazel is a girl from 1941 returned from the Underworld, while Frank is a son of Mars with hidden gifts inherited through Greek, Roman, and Chinese ancestry. The novel suggests identity is not simply what one remembers or inherits, but what one chooses to defend.
The burden and redemption of the past. Hazel’s chapters give the book its emotional gravity. Her cursed gems, her mother’s bargain, and her role in delaying Alcyoneus make her feel defined by guilt. Frank likewise carries family disgrace, grief for his mother, and the literal tinder of his mortality. The quest to Alaska becomes a symbolic return to old wounds: Hazel confronts the giant she helped raise, and Frank reclaims his lineage by mastering shapeshifting rather than hiding from it.
Sacrifice as the measure of heroism. Again and again, heroism is framed as costly choice. Percy gives up safety with June/Juno and later risks his life for a camp that may reject him. Frank burns his life-stick to free Thanatos, accepting death’s unfairness for the sake of everyone else. Hazel chooses Asphodel with her mother rather than private reward, then chooses life again by fighting for Frank, Percy, and Nico.
Unity across divisions. The Greek/Roman divide shapes nearly every conflict, from Octavian’s fearmongering to Juno’s dangerous exchange of Percy and Jason. Yet the novel repeatedly rewards coalition: the disgraced Fifth Cohort rises with Percy, Hazel, and Frank; Amazons and Romans unite against Polybotes; Tyson, Ella, Arion, and even Terminus become unlikely allies. The ending, with the Argo II approaching under fragile truce, turns this theme into the series’ central promise.
Death, justice, and second chances. With Thanatos chained, monsters return and moral order collapses. But the restoration of death is not comforting; Thanatos insists death is not fair. Against that bleak truth, the characters create meaning through mercy—saving Ella, trusting Hazel’s second life, and refusing to let the past have the final word.