The Lost Hero is the first book of The Heroes of Olympus series, written by Rick Riordan, who is also the author of the internationally famous Percy Jackson and the Olympians series. Unlike the books in the previous series, The Lost Hero is written in alternating third person points of view between Jason Grace, Piper McLean, and Leo Valdez, in contrast with Percy Jackson's first person point of view in the first series.
This time, the story tells of three unlikely friends: an amnesiac, an apparent kleptomaniac, and a mechanic who likes to play pranks, as they are thrown in together on a quest to save Hera, Queen of the gods, before she is lost to the world forever.
Origins and Development
Rick Riordan began writing a second series after realizing how many Greek and Roman myths he hadn't been able to explore and twist into tales for modern-day readers in the first series. After creating the story line, Riordan created three new main characters, Jason Grace, Piper McLean, and Leo Valdez, but kept the previous main characters, Percy Jackson and Annabeth Chase as secondary/main supporting characters. The narrative is told from the three main characters Jason Grace, Piper McLean, and Leo Valdez's perspectives. Although initially nervous, Riordan later found that most fans enjoyed the new format which allowed them to learn more of each character.
Riordan set the book two seasons after the events of The Last Olympian (during the winter) so that previous characters could be involved and so readers wouldn't be confused. He says that it was his way of letting his readers "revisit that world in a fresh twist, but also to catch up with Percy, Annabeth, and the rest of the gang from the first series."
He also decided to add the Roman gods after many readers requested for Riordan to write a new series on them, who were actually just the Greek gods with Roman names and slightly different personalities. After such requests, he began to think how the Roman aspect of the gods would be after moving from Greece to America. After a while, "playing with that idea gave me the idea for the new series."
Jason Grace wakes up with amnesia on a bus headed towards the Grand Canyon. He is sitting next to Piper McLean and Leo Valdez, who claim to be his girlfriend and best friend respectively. They explain that they, including the other kids on the bus, are from the Wilderness School, a school for delinquent or troublesome children where Piper had gotten sent to for allegedly stealing a BMW, although she claims that people "just give her things", and Leo by running away from his numerous foster homes.
When they reach the Grand Canyon’s skywalk, Leo and Piper try to get Jason to remember things as they remember them, but are unable to. Things get stranger for Jason when he finds a golden coin stamped with the word Ivlivs on its front. He is then approached by the chaperoning teacher, Coach Gleeson Hedge, who divulges that Jason must be the special package that the camp told Hedge to retrieve, along with two other half-bloods. Jason cannot understand the supposedly cryptic words that Hedge uses.
Their conversation is cut short when a storm appears, and a class member, Dylan, reveals his true nature as a storm spirit. Dylan causes a burst of wind to send Piper crashing against the doors of the skywalk and to push Leo to the edge of the skywalk. Hedge reveals himself as a satyr and goes to rescue Leo, but not before ordering Jason to fight Dylan off. Dylan, however, summons a blast of lightning and uses it on Jason. Amazingly, Jason survives, though he loses a shoe. By instinct, he pulls the coin out of his pocket and flips it, turning it into a golden sword. Dylan summons two more wind spirits, but Jason easily fights them off.
A hole opens up in the clouds, and Dylan states that his mistress is calling. He then decides to take Jason, but is stopped when a recovered Piper climbs onto his back. The wind spirit shakes her off, and she falls into the canyon. Hedge is taken instead, and both the wind spirit, Hedge, and the storm disappear. Jason then saves Piper by diving into the canyon and using his sudden abilities to control the winds to bring them back to the skywalk.
Two demigods, Annabeth Chase, a daughter of Athena, and Butch, a son of Iris, suddenly appear on a pegasi-drawn chariot. They claim that they are looking for a half-blood who has been missing for three days, and that the answer to finding that half-blood was with the 'guy with one shoe' ― Jason. Though the Jason knows nothing and though Annabeth and Butch do not find who they are looking for, they all board the chariot anyway and go to Camp Half-Blood.
After they crash in the lake due to some other unruly storm spirits, Leo is almost immediately claimed by Hephaestus, the god of fire and forges. He is then taken by the Apollo head counselor, Will Solace, to see his new cabin and siblings. Meanwhile, Annabeth notices tattoos on Jason’s arm: a dozen straight lines, an eagle, and the letters SPQR. Unsure of what to do with him, Annabeth allows Drew, the tyrannical Aphrodite head counselor, to take Jason to Chiron in the Big House. Annabeth then gives Piper a tour of the camp. There, Piper manages to claim the dagger Katoptris as her own weapon.
Piper is suddenly drawn to Hera's cabin, leaving Annabeth no choice but to follow her. There, they see a figure wrapped in a shawl. The figure is revealed to be Rachel Elizabeth Dare, the Oracle. Rachel and Annabeth talk about Percy for a while before Annabeth remembers to introduce Piper to Rachel. A goddess then suddenly appears to Piper by possessing Rachel. The goddess warns Piper of the fiery giant that Piper constantly sees in her nightmares and commands Piper to free her. Piper then loses consciousness.
On his way to Cabin 9, Leo manages to catch a glimpse of his former babysitter, Tía Callida, but she immediately vanishes. He brushes this aside and allows Will to teach him how to find his own place at camp. Will goes on to explain that the cabin appears to be under a curse since Charles Beckendorf’s death. None of their machines are working and they are burdened with a problem that is disturbing the entire camp. Will then leads Leo into the forges and leaves him in the hands of the Hephaestus kids.
There, Leo then learns of the problem they need to fix: a bronze dragon that Beckendorf managed to tame has gone haywire and is hiding in the forest, destroying everything in its path, disrupting campers and eating satyrs. He also learns that the ability to manipulate fire, an ability he possesses that he has made a well-kept secret, is a rare trait among Hephaestus' children and is a dangerous power due to it normally bringing destruction to the area around them. Leo is shocked at this, as he recalls when he accidentally used his fire powers during his childhood and killed his mother.
Meanwhile, Jason is brought to Chiron, who is puzzled at Jason being at the camp. The two talk, and when Chiron switches to Latin, Jason immediately answers in the same language. Then, time seems to freeze in the room and Jason has a vision of a goddess asking him for assistance. When the vision ends, he relays the vision to Chiron. This gives Chiron some clues as to who Jason is, but he does not voice aloud these thoughts. At that moment, Rachel and Annabeth enter the room, stating that Piper is in a weak state. As Chiron heals Piper, they all share notes about what has recently happened: Jason’s vision and the possessing of Rachel. They also talk about the fact that Zeus has recalled all the gods to Olympus and closed off all communications to the mortal world.
They then conclude that the goddess who is behind both appearances to Jason and Piper is Hera. Later, Annabeth takes Jason to Hypnos' cabin as she explains that his memories might be brought back there. He, however, does not regain his memories, but instead learns from Clovis, the head counselor of Hypnos, that his memories were actually stolen by Hera. It is also there that Annabeth and Jason learn the truth about the gods ― no matter what name they are called by, Greek or Roman, they are all just the same gods with slightly different personalities.
While unconscious, Piper dreams of the last day she spent with her father. The dream changes to a view from the top of a mountain. There, Piper sees the fiery giant who tells her to do as he says and go on the quest, though she does not know what he is talking about. She then sees her father bound on a stake before she comes to. She sees Rachel by her side, and they talk for a while before Rachel lets her know that it is time for the campfire.
A Quest is GivenZeus (whom he initially calls Jupiter) by flipping his coin this time turning it into a lance, and calling a bolt of lightning down from the sky. He then accepts a quest to save and release Hera from her bonds by the winter solstice in four days. Rachel Elizabeth Dare issues a new prophecy that demands the need for a child of Hephaestus and a child of Aphrodite to accompany Jason. Leo volunteers and Jason accepts with the one condition that Leo must find air transportation as Rachel’s prophecy warns them to beware the earth.
Drew volunteers to go on the quest as well, but Piper intervenes. Drew, however, reminds them that Piper is still unclaimed and because of this, is forbidden to go on any quests. Piper insists and unknowingly uses charmspeak on the listeners. Their argument is cut when Piper is suddenly dressed in a Greek chiton and surrounded by a pink aura. It becomes apparent that she has been claimed by Aphrodite as the goddess gives Piper her blessing, thus allowing her to venture on the quest. She is then proclaimed as the third quest member.
After being claimed, Piper is given a bunk at the Aphrodite cabin, but Piper quickly learns how Drew treats those under her. Drew uses her charmspeak to always get her way and punish anyone that disagrees with her. Drew also forces any new members to perform an initiation ceremony, which is to make someone fall in love with them and then break their heart. Drew believes that breaking hearts is what love is all about (after mistaking the true reason Aphrodite always leaves her lovers), and that Silena Beauregard's and Charles Beckendorf's death was a result of Silena breaking the tradition. Piper disagrees that breaking hearts is what love is really about, but Drew turns the tables on her by asking what love is really all about if not breaking hearts. When Piper can't think of a response, Drew only continues to mock her.
Leo is able to obtain air transportation by managing to fix the bronze dragon, who he names Festus (happy in Latin). Festus leads Leo to an underground workshop where Leo finds wings and attaches them to the dragon. Jason, on the other hand, explores the Zeus cabin while waiting for the transport. He then finds some pictures that the former occupant, Thalia Grace, had left behind. These photos include one which shows Thalia, Luke Castellan, and Annabeth before they had reached camp. At that moment, Annabeth comes in.
Annabeth tells him to follow the wind spirits that had attacked them as their master might know where Hera is. She also tells him that it might be better to go directly to Aeolus, the master of the winds. And in order to find him, they must interrogate one of the four seasonal winds under his control ― preferably the god Boreas in Canada as he is the friendliest. Their conversation drifts to the pictures on the wall, and Jason asks after Thalia.
Annabeth gives him a brief history of Thalia’s life, including her family name. A shard of Jason’s memory ignites, and he asks Annabeth to keep a secret what he would divulge to her. She hesitatingly swears on the River Styx, and Jason reveals to her what he now remembers: his family name is Grace, and Thalia is his sister. Annabeth does not have time to voice her thoughts about this revelation as Leo appears outside with Festus. The three quest members then set off.
The North Wind
The trio makes it to the top of Boreas' penthouse in Quebec, when they are met by his sons, Calais and Zethes. A fight almost breaks out, but Piper uses her charmspeak to convince the two Boreads to allow them to enter the residence. Once inside the icy penthouse, they meet Boreas' daughter Khione, the Greek goddess of snow, whom Leo almost immediately feels an attraction to despite the fact that she is very cold, both literally and figuratively. Calais and Zethes do not let Leo go in the throne room as Festus may cause trouble. Though Leo manages to compact him into a briefcase, they still do not permit Leo to enter as they can detect that he can summon fire. Jason and Piper than proceed to meet Boreas.
While speaking to the North Wind, Piper is revealed to be able to speak French as it is the language of love. Boreas then tells them that Aeolus is angry with the gods when they defeated Typhon in the war as it had released a wave of wind spirits, and he is expected to control them. Because they are gods, Boreas explains, Aeolus cannot take out his anger on them and instead, does so on their children, the demigods. This is why Boreas and the winds under Aeolus’s control have orders to kill any demigod who asks for help. Jason, however, is a son of Zeus, and Boreas and his company have been told to wait for one of Zeus’s children and hear that child explain before they pass judgment.
Jason is too nervous to explain his side, but is saved when Piper does so instead. Boreas then tells them that he knows the storm spirits who attacked them on the Grand Canyon and where the mistress resides ― the windy city of Chicago. Suddenly, Jason's mysterious tattoo makes Boreas to turn into his Roman form of Aquilon. It then becomes apparent that Aquilon has realized what Hera is doing, but does not share his thoughts and instead lets them go, much to Khione’s displeasure.
As they travel to Chicago, Piper dreams of the fiery giant again. This time, she can no longer see her father tied to the stake. The giant, who reveals his name as Enceladus tells her to come to him at noon on the solstice, and she may live with her father. He tells her to betray Hera and her friends for they have all done nothing for her, but she refuses to.
Piper wakes just as Festus falls from the sky. Jason manages to grab her and Leo and keep the three of them from free-falling before Festus crashes onto the ground. Jason loses control of the winds and they fall into a warehouse below. They then figure out that they are in Detroit. Sensing that they need a moment in private, Leo goes out to find and try to fix Festus and leave the two inside.
Leo discovers out that the control disk of the dragon had iced over, which is quite impossible as it must have been too hot for ice to form. He summons supplies from his magic tool belt and cleans the disk. While doing so, he then sees the figure of an earthen woman: the same woman who had appeared to him that fateful night in his mother’s workshop, and the real reason why his mother had died. The woman tries to convince Leo to leave his friends, but Leo refuses to and instead smashes the woman with a nearby Porta-Potty. He then hears a commotion inside the warehouse and summons a hammer before he goes in.
There, he finds that three Cyclopes have captured Jason and Piper inside their closed down car plant. Leo builds a remote control and attaches it to some robotic cranes which he uses to destroy two of the Cyclopes. He then manages to bait the third Cyclops, Ma Gasket, under a car engine held by a rusting metal chain. He shoots out a concentrated burst of fire from his fingertips which causes the chain to snap and release the weight, flattening the Cyclops. However as they celebrate their victory, Ma Gasket and her two sons, Sump and Torque, instantly begin to reform.
The Sorceress and the Gold King
They then reach Chicago and follow some wind spirits which go into a sewer. Leo sends Festus off but not before telling the dragon to come when he blows on a plastic whistle that he summons from his toolbelt. While camping in the sewers, Leo talks about his fire abilities, branding it as a curse, but Jason retorts and calls it a gift. After getting some sleep, they explore the sewer and find an elevator with a directory on its side. They ride the elevator to a shopping mall owned by a beautiful older woman who introduces herself as the Princess of Colchis.
The princess invites them to shop for a while, and though Piper is immediately subrotherious of her, Jason and Leo follow the princess's orders without fault. They then spot Coach Hedge in a cage where he is still frozen in a fighting stance. Meanwhile, the woman is impressed that Piper has not succumbed to her enchantment, and reveals that she is using charmspeak on the boys.
The princess orders Jason and Leo to fight each other and almost do so, but by this time, Piper has figured out who she is and tells the two: the princess is the sorceress Medea. Jason and Leo are still ready to fight though, and to weaken Piper's resolve, Medea publicly reveals that Piper's father is captured by the giant Enceladus. Piper, however, manages to snap the two out of their trance, and the three turn on her. In retaliation, Medea sets free two Sun Dragons, gifts from her grandfather Helios, which are easily defeated by Festus. They then escape with Coach Hedge and a cage full of venti in tow. They then fly towards Aeolus' fortress by following a vapor trail which is only visible to Jason.
Leo later has a dream in which his father, Hephaestus, appears to him for the first time. Hephaestus explains that Zeus closed off Olympus because he felt that it was high time that the gods return to traditional ways where they were more distant with the mortal world. In addition to that, the bad things that were happening may be stopped if the gods withdrew from the world. Hephaestus then tells Leo that he has watched over Leo throughout his life, and that he gave the gift of fire to him for a reason. Hephaestus cryptically adds that nothing lasts forever, but that everything can be reused before disappearing.
Leo wakes to a malfunctioning Festus as the weight of three people and two cages is clearly too much for the dragon. Leo tells Jason to take Piper and fly away as he tries to fix the dragon. He manages to direct Festus to a yard near a mansion for landing when Festus is shot out of the sky by lasers. When Leo comes to, he is being attended to by Jason and Piper. He then sees that Festus's body is destroyed, with only his neck and head intact. Leo prays to his father to take the intact parts to Bunker 9, and Hephaestus obliges. They figure out that the lasers must be part of the defense mechanism of the house. With nowhere else to go, they enter the house.
They discover that it is being resided in by King Midas. He is revealed to be against their side as he asks them if they would rather join his collection of gold statues or be killed by his son Lityerses. Before they could answer, Midas turns both Leo and Piper to gold. Jason chooses to fight Lityerses and defeats him by using a Roman style of fighting. He then manages to trick Midas into turning Lityerses into gold. Jason summons a bolt of lightning to let rain into the roof, allowing the running water to return to normal all of the gold statues. With the help of Hedge, who is now conscious, Jason takes his friends and the four of them escape.
While resting in a mountain cave after returning Leo and Piper back to normal, Piper reveals the secret she had been carrying the whole time: the giant Enceladus had ordered her to sabotage the quest in return for the safety of her father. She expects the group to turn their back on her, but is relieved when they comfort her instead and tell her that they would rescue both her father and Hera.
The group is suddenly attacked by Lycaon and his group of werewolves. The group tries to attack the werewolves with their weapons when they discover that only silver can wound the werewolves. On cue, silver arrows shoot the werewolves and the monsters retreat. The Hunters then appear, with Thalia Grace in the lead. Thalia then orders the other Hunters to follow Lycaon's trail. As Piper has contracted hypothermia, Thalia asks the remaining Hunter to take care of Piper and the satyr, leaving her with Jason and Leo, the latter being immediately attracted to her. Leo sense that the two siblings need to be alone and turns to leave, but Jason asks him to stay. Thalia grudgingly accepts his company.
Thalia explains to Jason that their mother was visited by Zeus twice. After Zeus left their mother for the first time, she got worse and began to act irrationally, seeing getting Zeus' attention as the ultimate prize. When Zeus came back a second time, she was happy and got better. Thalia noticed that he was stricter and spoke in Latin sometimes. He left their mother for good the second time as she had pestered him to give her immortality. Then, one day, their mother had driven them to a place that they had always known ― the Wolf House. She left the car with Jason and came back without him. Losing Jason was the last straw for Thalia, and she ran away. Thalia adds that their mother died driving while drinking. She then tells the two that Artemis had set them on the trail of Lycaon as it would lead them to their missing friend.
Thalia then leads them to Aeolus' palace (a floating mountain), and in order to enter, they must cross a frozen bridge. As they are crossing, Leo suddenly gets an idea. He voices this out loud and says that perhaps Jason was a bridge between two places ― an exchange. As an exchange goes both ways, then the missing half-blood must be the one sent to the other side. Basing his thoughts from Jason's dream, he also says that Hera is kept in the Wolf House. He gets excited by these ideas that causes himself to burst into flames, thus melting the ice bridge while Thalia still has yet to cross it. Thalia tells them that the Hunters will go to the Wolf House and hold it while they rescue Piper's dad from the giant. She also says that Jason already knows where it is and that they'll meet again soon.
Aeolus and the Real Enemy
They go up the mountain and are escorted by an aura, Mellie, the assistant of Aeolus whom they mistake for a ghost. When they finally meet Aeolus, he turns out to be a weather reporter-type figure who gets his commands from the gods, and therefore his forecasts, from the gods. Because the gods are constantly changing their decisions, it causes Aeolus to do the same to his forecasts. The group concludes that because of all this chaos, Aeolus must be mad. Aeolus then explains that because he is the master of the winds, all things carried by the winds, secrets included, come to him in time. The group proceeds to give him the caged venti, both as a gift and to be in his good graces.
Aeolus then stops the order to kill demigods and tells them that he was just cranky. Through an earpiece, the children's godly parents order him to reveal the location of Enceladus at Mount Diablo, and he obliges. He also gives Leo the crayon drawing he had done when he was much younger, explaining that all things lost come to him eventually. He is about to send them on their way when he gets a call from an anonymous source that tells him to kill the group. He relays this message to them and says that the authority of the caller overrules the authority of the gods, and therefore he must comply to the caller's wishes. He then sends his harpies to kill them.
The group dash to one of the many tunnels of the mountain leading to the open air. Mellie, who has formed an attachment to them (especially to Hedge), helps them escape. She and Jason are able to control the winds to cushion their fall. As the violent winds chase after them, Mellie wraps them in a breeze just as the winds hit.
Piper opens her eyes to see her mother, Aphrodite, standing before her. They are back in Medea's department store. Aphrodite advises her daughter by telling her that being a child of Aphrodite does not mean just being a pretty face. She goes on to explain that some of her children are destined for greatness due to her unique lineage. Aphrodite then gives Piper two things ― a vial filled with a potion that only erases recent memories and an invaluable piece of information. Aphrodite reveals the identity of their true enemy, the most ancient goddess and the mother of all ― Gaea.
Piper wakes to see that the group has been transported to San Francisco, courtesy of Aphrodite. She then discusses what she has learned to the group. They see Mount Diablo in the distance and prepare themselves for what they might encounter.
They get to Mount Diablo via taxi. The males of the group try to distract Enceladus while Piper frees her dad, but Hedge is almost immediately knocked out. As soon as Piper's father is free, the giant summons Earthborn to kill them. Leo manages to get a hold of a construction crane to destroy most of the Earthborn, and Piper kills the last. Jason fights Enceladus, but is unable to defeat the giant as he is being aided and healed by the earth. Jason’s lance is then destroyed and unleashes an explosion that blows a massive crater on the mountain. With nothing to combat Enceladus with, Jason then prays for assistance from his father, offering his life in return for help. Zeus answers, and his lightning bolt transfers through Jason into the giant, who falls into the crevice it creates, for the only way to kill a giant is for a god and a hero to kill it together.
The Wolf House
The group gets a helicopter with Piper's charmspeak ability, and they are flown to Oakland Airport. During the trip, Tristan McLean is visibly shaken by his experience, causing Piper to make the decision to give him the vial Aphrodite had given her as soon as they land. She does so, and Hedge volunteers to take Piper's father to safety. Leo then flies the same helicopter they used and they travel to the Wolf House. The group crash-lands and joins the Hunters of Artemis as Thalia rushes to meet them.
They find Hera in a cage made from earthen tendrils as the giant Porphyrion uses her power to reform himself. Leo then reveals Hera as his former baby-sitter in the guise of Tía Callida. Thalia leaves to help her Hunters, and Leo tries to find a way to destroy Hera’s cage. Khione, the goddess of snow, appears and reveals herself to be the reason for two things ― Aeolus order to kill the demigods and Hera’s coming to the Wolf House. She then explains that, like snow, her voice is soft, gentle, and very cold. This allows her to easily manipulate the thoughts of the gods.
Khione goes on to tell them that because the Wolf House is a sacred place for Jason’s group of demigods, they would be appalled when they discover his corpse with the bodies of his two Greek companions. This would cause them to think that the Greeks had conspired with the giants, causing a war between both lines of demigods. She then offers Leo a place beside her as she knows that he is attracted to her. Leo is stunned, but he refuses and charges to fight her.
While Leo combats Khione, Piper holds her own against the Earthborn. Jason manages to get a hold of a storm spirit and rides it as he incapacitates enemy wolves. As the Earthborn and the wolves are defeated, Khione flees from the battleground. Leo and Piper then try to destroy Hera’s cage by sawing through it and using charmspeak to lull it to sleep respectively. Porphyrion, however, is able to rise, and Jason has to choice but to fight him. The fight is almost hopeless for Jason, though, and he is about to be killed when the two manage to free Hera.
She then assumes her divine form which obliterates all other monsters in the area. Porphyrion does manage to escape. Jason accidentally looks at the goddess in that state, and is knocked unconscious and apparently dies. Piper, however, is able to save him by using charmspeak on him while coaxing him to wake. Hera congratulates them, and, though she has a little spat with Thalia, brings the trio back to Camp Half-Blood.
A Change of Power and Bunker 9
After the quest, Piper challenges Drew Tanaka to a duel for the position of Aphrodite head counselor as Drew had turned the Aphrodite cabin into a group not above twisting the meaning of love and beauty. Drew backs down from the duel, allowing Piper to become the head counselor of the Aphrodite cabin. Later, Piper and Jason share a moment before coming with Leo as he reveals the entrance to Bunker 9 and his fire ability to Chiron and the Hephaestus' cabin. There, they find many blueprints and diagrams of inventions. In addition, they find a map of the camp crisscrossed with weaponry. They wonder why the pace and everything in it was built.
Leo guesses that the bunker used to be a command center when the camp was attacked in a war. They speculate that this means the Titan War that had happened months ago, but realize that the map looks much older. Chiron then tells them that map was from the last Civil War, which had another side to it as being the battle between two different demigod groups. The war caused so much grief and bloodshed that the gods put all their will and power to separate them as much as they could. The bunker, Chiron goes on, was only visited during times of great unrest as it awakens many horrible memories.
Leo then shows them the blueprints for an aerial warship on a board and the drawing he did as a child. The people present are amazed because the two are completely similar, and the blueprints must have been made a century ago. They also realize that Festus' head is the masthead. The Hephaestus cabin decides to take the project even though they only have six months to build the warship. Leo is then proclaimed head counselor of the Hephaestus cabin and names the ship the Argo II. As the giants had mentioned that the gods must be destroyed at the roots, the trio make plans to travel to and protect the gods ancient homeland in Greece.
Mysteries are Unveiled
While in Cabin One, Jason Grace is visited by Juno. She promises to watch over him as his patron and gives him a new gladius to replace Ivlivs. Piper then comes in to bring him to the council of cabin leaders. At the council, Jason reveals that both Greek and Roman demigods were never aware of each other. While the Romans conquered the Greeks and the Greeks had thought the Romans were barbarians, they had always respected each other ― the Romans for their military prowess, and the Greeks for their rich culture.
Jason also reveals that during the Titan War last summer, the Roman demigods were the ones who stormed Mount Othrys and he himself defeated the Titan Krios. The council decides on a plan: build the Argo II and find the Roman camp in San Francisco. Annabeth then asks to come with them. Jason accepts as they reveal that the missing half-blood ― Percy Jackson ― as the war leader of Camp Half-Blood, was traded with Jason to the Roman camp and has probably no idea who he is.
This book's prophecy is given to Jason Grace:
Child of lightning, beware the earth,
The giants' revenge the seven shall birth.
The forge and dove shall break the cage,
And death unleash through Hera's rage.
Unraveling of the Prophecy
- Jason, a child of Jupiter, has to beware of the awakening of Gaea, the Earth.
- The giants' rise to defeat the Olympians will cause the appearance of the seven heroes of the Great Prophecy.
- Leo and Piper, children of Hephaestus and Aphrodite respectively, break the cage Hera is trapped in.
- Hera goes into her Divine Form and kills all the monsters in the area, except for Porphyrion who flees before she unleashes her full power.
There are no chapter titles. Each chapter has a name of one of the main characters and is written in Roman Numerals. There are 56 chapters going alternately in the order of Jason, Piper then Leo. Each character gets two chapters before it shifts to another character.
|Jason||I, II, VII, VIII, XIII, XIV, XIX, XX, XXV, XXVI, XXXI, XXXII, XXXVII, XXXVIII, XLIII, XLIV, XLIX, L, LV, LVI|
|Piper||III, IV, IX, X, XV, XVI, XXI, XXII, XXVII, XXVIII, XXXIII, XXXIV, XXXIX, XL, XLV, XLVI, LI, LII|
|Leo||V, VI, XI, XII, XVII, XVIII, XXIII, XXIV, XXIX, XXX, XXXV, XXXVI, XLI, XLII, XLVII, XLVIII, LIII, LIV|
- Jason Grace: A 15 year-old son of Jupiter who has lost his memory; he is also the long-lost younger brother of Thalia Grace. He comes from Camp Jupiter and is one of the leaders at that camp who are called praetors. He has a golden coin stamped with Julius Caesar's face on one side and a battle axe on the other that turns into a lance, or a double-edged sword made of Imperial Gold depending on the flip. He and Percy seem to share the fatal flaw of personal loyalty. He is also attracted to Piper McLean.
- Leo Valdez: He's Jason's best friend and a son of Hephaestus and is very mischievous. He also likes to build things and is constantly busy with tools. Leo is a fire user; the first in hundreds of years. He is fireproof as well. This is a very rare ability because very few children of Hephaestus are given this gift as it is very dangerous. Leo often uses humor to compensate for the immense sadness he feels from his past.
- Piper McLean: She is a daughter of Aphrodite who can charmspeak, a very rare talent that is used to charm most people into doing anything. She is also attracted to Jason Grace. She becomes the head counselor of the Aphrodite cabin after she challenges Drew to a duel, and the latter backs down.
- Gleeson Hedge: He's a satyr posing as a middle school P.E. coach who was assigned to protect Leo and Piper. He sees through the Mist when Jason shows up on a school bus. He can be overprotective and rational at times.
- Thalia Grace: Jason's biological sister. She is very fond of her brother and ran away when he disappeared. Their family is one that has never been seen before: two children, one a child of Greece and the other a child of Rome, born to the same mother by the same god. She is the lieutenant of the Hunters of Artemis.
- Juno: The queen of the heavens. When Jason was 2 years old, he was given to her by his mother to be her champion. She was captured by Gaea to be used to hasten the giants return. She was the one who stole the memories of both Percy Jackson and Jason Grace. Her Greek form, Hera, used to baby sit Leo when he was younger under the guise of Tía Callida, and often put him in dangerous situations to test if he was worthy.
- Annabeth Chase: A 16 year-old daughter of Athena and a main character from the previous series. Annabeth arrives in a flying chariot with a demigod named Butch, on account of the dream Hera sent her, telling her to go to the Grand Canyon and find the answer to Percy Jackson’s mysterious disappearance.
- Clovis: He is a son of Hypnos and the head of Cabin Fifteen. Clovis is the one who confirms that Jason's memories were stolen, specifically by Hera/Juno, and is partly the reason for the quest to save Hera. Clovis, being the son of the god of sleep, is able to manipulate dreams and see things in his dreams.
- Dylan: He is a cruel boy who reveals his true identity as an Anemoi Thuelli. He is a storm demon (a son of Typhon) or a storm spirit and tries to kill Jason, Piper, and Leo. Later in the story, his mistress is to be revealed as Medea.
- Butch: He is a son of Iris, and the head counselor of the Iris cabin. He arrives with Annabeth on a chariot pulled by a pair of pegasi. There is a rainbow tattoo on his arm as Iris is the goddess of the rainbow.
- Medea: A sorceress. She is one of the people who returned to the living world after Gaea had opened the Doors of Death. She almost succeeds in killing Jason, Piper and Leo. She is killed in a fire in her department store after the three mentioned demigods escape.
- King Midas: A mortal brought back to life after the Doors of Death were opened. He temporarily delays the Jason, Piper, and Leo in their quest after turning the last two into gold. He is defeated by Jason.
- Drew Tanaka: Drew is a daughter of Aphrodite at Camp Half-blood. She can also charmspeak. She seems to dislike Piper very much, and has feelings for Jason. She was the leader of the Aphrodite's Cabin at the beginning of the book before Piper forced her to step down. She often twists the meaning of love and forces her cabin-mates to do the same.
- The US cover depicts Jason Grace, Leo Valdez, and Piper McLean flying away with Festus from Boreas' palace, yet Piper is still wearing her outfit from Aphrodite despite taking it off before they went on the quest.
- This book, along with The Blood of Olympus, is the only one in The Heroes of Olympus series where the title does not include the name of a god.
- Medea's products have been mentioned before. In The Sea of Monsters, Annabeth regrets leaving a jar of "Medea's Sunscreen FPS 50,000" on her nightstand when she and Percy arrive at Half-Blood Hill at the beginning of the story.
- The Lost Hero begins on a school bus with Jason, Piper, and Leo travelling to the Grand Canyon, this parallels the start of The Lightning Thief which also begins on a school bus with Percy's class travelling towards the Metropolitan Museum of Art.
- The trio met Zethes and Calais (sons of Boreas). In the myths, they helped the original Jason (Quest for the Golden Fleece) in the quest by warding off the harpies that hound Phineas, the blind seer, in exchange for information. Later in The Son of Neptune, Percy, Hazel and Frank meet Phineas in Portland.
- It's unknown if the title, The Lost Hero, refers to either Jason or Percy, due to the fact that both share many aspects of the title.
- Jason doesn't know who he is, doesn't know if he belongs in Camp Half-Blood, and is very confused since the beginning of the book.
- Percy, "The Camp's Hero", has been missing for days and has yet to be found at all.
- Tartarus is once mistakenly spelled as "Tatarus". 
- The Lost Hero is the only Heroes of Olympus book that Percy Jackson does not appear in, although there are several references to him.
- In The Lightning Thief, it is mentioned that there are central bathrooms that all of the cabins have to share, but in The Lost Hero, there is a bathroom in the Aphrodite cabin.
- In the novel, Aphrodite explains to Piper that mortals cannot comprehend the truth about the gods, and are driven mad by the realization. Although this is true in the case of Piper's father and Thalia and Jason's mother, there are numerous exceptions. Sally Jackson was well aware of who Poseidon was and the truth about gods, yet she remained sane. The same went for Annabeth's father, Fredrick, who was well aware of who Athena was and even met Artemis as well. Also, Magnus Chase's mother, Natalie, knew who Frey really was, and remained sane. May Castellan knew who Hermes was and remained sane(her insanity was caused by her attempt to become the new Oracle.)
- This the only book in the series whose title is not mentioned in 'The Blood of Olympus'
- ↑ Chapter 50, page 508