Rescued when Percy takes her place holding the sky temporarily. Helps in the final battle against...

Appears at the Winter Solstice meeting on Olympus. Supports his sister Artemis and helps decide the...

God of war present at the Winter Solstice council meeting on Olympus.

Found captured by Atlas, forced to hold up the sky in his place. Freed when Percy temporarily takes...

Various demigods at Camp Half-Blood dealing with the crisis of having three Big Three children...

The strawberry fields at Camp Half-Blood that help fund the camp through sales to mortals.

Helps organize the quest to rescue Artemis and provides guidance to the questers. Understands the...

One of the younger hunters of Artemis who helps train new recruits like Bianca.

Daughter of Ares and head counselor of the Ares cabin at Camp Half-Blood.

Son of Hermes and one of the Stoll brothers known for their pranks and thievery.

Goddess of agriculture present at the Winter Solstice council meeting on Olympus.

Hunter of Artemis who joined during a full moon ceremony centuries ago.

Continues the quest while worried about Percy, who has gone missing. His empathy link with Percy...

God of the Underworld present at the Winter Solstice council meeting on Olympus.

God of fire and metalworking who owns the junkyard. Creator of many automatons and mechanical...

God of messengers present at the Winter Solstice council meeting on Olympus.

Welcome Thalia Grace as their newest member after she chooses to join them rather than face the...

One of the more recently recruited hunters, joined within the last century.

Daughter of Demeter and head counselor of the Demeter cabin, expert with plants.

Son of Athena and temporary head counselor while Annabeth is missing.

Attends the Winter Solstice council meeting on Olympus. Participates in deciding the punishment for...

Young hunter of Artemis who specializes in night combat and stealth operations.

Blames Percy for Bianca's death and runs away from Camp Half-Blood. His powers over death and...

Revealed to have the power to destroy Olympus if its entrails are burned by an enemy of the gods.

Helps defeat Atlas and rescue both Artemis and Annabeth. Takes on some of Atlas's burden...

Son of Dionysus and twin brother of Castor, skilled with vine magic.

God of the sea present at the Winter Solstice council, defending his son Percy's actions.

Daughter of Aphrodite and head counselor of the Aphrodite cabin.

Joins the Hunters of Artemis to avoid the burden of the Great Prophecy and finds a new family with...

A new constellation created by Artemis to honor Zoë Nightshade after her heroic death.

Magical force that obscures supernatural events from mortal perception.

Son of Hermes and head counselor of the Hermes cabin, known for leading pranks.

Taxi driver who witnesses strange events but sees them through the Mist.

Recently arrived half-blood who hasn't been claimed by a godly parent yet.

Hunter specializing in forest warfare and woodland tracking.

Goddess of love and beauty who appears to Percy in the junkyard. Gives cryptic advice about love...

Ancient Greek hunter who has served Artemis since classical times.

One of Artemis's hunters who arrives with Zoë to fight Dr. Thorn. Known for her incredible speed.

Battles the heroes and kills his daughter Zoë before being tricked back into his eternal punishment...

Bronze mechanical warriors created by Hephaestus to guard his junkyard. Attack intruders...

Twin sons of Ares with bear-like features who serve Luke and the Titan forces.

Friendly waitress at a local diner in Cloudcroft who serves travelers.

Dies in Hephaestus's junkyard while trying to retrieve a figurine for Nico. Her death fulfills part...

Long-haul truck driver who gives Percy and Nico a ride.

Local cattle rancher who reports strange animal behavior to authorities.

Helps Percy travel across the country by air, providing crucial transportation during his...

Parking lot attendant who directs tourist vehicles at Hoover Dam.

One of Annabeth's young half-brothers, son of Frederick and Mrs. Chase.

Son of Athena studying under Malcolm while Annabeth is missing.

Mechanical bronze warriors guarding Hephaestus's junkyard, programmed to attack intruders.

One of the younger cadets at Westover Hall attending his first school dance.

One of the military cadets at Westover Hall participating in the dance.

Military cadet at Westover Hall who witnessed the strange events at the dance.

A military cadet at Westover Hall present at the school dance.

Military cadet at Westover Hall who attended the school dance.

A military cadet at Westover Hall attending the school dance.

The lake at Camp Half-Blood where water activities take place, home to naiads and other water...

The forest surrounding Camp Half-Blood where capture the flag is played and various creatures live.

San Francisco fire captain responding to emergency calls during the battle.

Museum maintenance worker who cleans exhibits and handles minor repairs.

Operator who monitors the dam's turbines and water flow systems.

Son of Dionysus and twin brother of Pollux, head counselor of Dionysus cabin.

Son of Hephaestus and head counselor of the Hephaestus cabin, expert metalworker.

Regular customer at a San Francisco coffee shop who witnesses unusual activity.

Ancient celestial bronze weapons and mechanical devices created by Daedalus, used by Frederick...

Hunter of Artemis skilled with a bow, part of Zoë's rescue team at Westover Hall.

New camper who arrived with electronic gadgets that keep malfunctioning.

Hunter who joined Artemis during the Roman era, bringing knowledge of Roman hunting techniques.

Elderly woman touring Hoover Dam with her husband, taking photos.

Museum curator specializing in ancient Greek and Roman artifacts.

Captures Annabeth during the battle and escapes with her. His mission was to bring the di Angelo...

Daughter of Aphrodite with a mean streak and powerful charmspeak abilities.

Group of elementary school children on a museum field trip, excited about dinosaurs.

The psychic connection between Percy and Grover that allows them to sense each other's emotions and...

Engineer working at Hoover Dam who monitors structural integrity.

Group of college engineering students studying dam construction.

A massive wild boar that the group encounters during their journey. Large enough to carry multiple...

Annabeth's mortal father who lives in San Francisco. Professor and expert in military history.

The mysterious 'General' leading the Titan forces, revealed to be Atlas himself after being freed...

Elderly retired man visiting Hoover Dam with his wife on vacation.

The headmaster of Westover Hall military academy, responsible for school administration.

Military helicopter pilot who helps Frederick Chase during the battle, controlled by Daedalus's...

Nymphs who guard the Garden of the Hesperides where Atlas once held up the sky. Daughters of Atlas.

Tour guide at Hoover Dam who gives information about the dam's construction and history.

Mortal tourists visiting Hoover Dam who are oblivious to the supernatural events happening around...

Goddess of the rainbow who provides Iris-messaging services for divine communication.

Magical communication system using rainbow mist, operated by the goddess Iris.

Son of Hephaestus working under Beckendorf in the forges.

Enthusiastic museum tour guide who leads school groups through exhibits.

Local news reporter covering the strange incidents in San Francisco.

Owner of the local gas station in Cloudcroft who notices unusual travelers.

Hunter of Artemis known for her fierce temperament and skill with wild animals.

Food service workers at Westover Hall who prepared refreshments for the dance.

The disembodied voice of Kronos that speaks to Luke and influences his actions toward evil.

Poisoned Zoë with its venomous breath during the battle at the Garden of the Hesperides.

Son of Apollo and head counselor of the Apollo cabin, skilled archer and healer.

Stone lion statues that come to life in Hephaestus's junkyard to attack intruders.

University student who takes photos of the helicopters and strange events.

Battles against his former friends during the confrontation with Atlas. Shows no mercy toward those...

Hunter of Artemis who specializes in moonlight combat and lunar magic.

Supervisor of maintenance operations at Hoover Dam.

School maintenance worker who keeps Westover Hall clean and secure.

A monster with a human head, lion body, and scorpion tail that shoots poisonous spikes.

Owner of a small general store who sells supplies to travelers.

Frightened new arrival at Camp Half-Blood who witnessed monster attacks.

One of the oldest hunters of Artemis, second only to Zoë in experience and wisdom.

One of Annabeth's young half-brothers, son of Frederick and Mrs. Chase.

Small son of Apollo with exceptional archery skills despite his size.

Worker in the Hoover Dam power plant monitoring electrical generation.

Stern military instructor at Westover Hall who maintains discipline among the cadets.

Daughter of Demeter who helps Katie with the strawberry fields.

Mountain nymphs and spirits dwelling in the areas around Mount Tamalpais and Mount Othrys.

Mathematics teacher at Westover Hall helping supervise the school dance.

Annabeth's stepmother who has a tense relationship with her stepdaughter.

Administrative secretary at Westover Hall who handles school correspondence and records.

Teacher at Westover Hall serving as chaperone for the school dance.

Owner of a small shop in San Francisco who sees helicopters and strange activity.

School librarian at Westover Hall who manages the academy's library resources.

Elementary school teacher leading a field trip to the museum.

Clerk at a roadside motel who checks in weary travelers.

Various nature spirits that Grover can communicate with during their journey through the wilderness.

A massive lion with impenetrable golden fur that attacks the quest group. One of the monsters sent...

Medical nurse at Westover Hall who tends to student injuries and health needs.

San Francisco police officer who responds to reports of unusual activity.

Night security guard at the museum who investigates strange noises and disturbances.

Elderly groundskeeper at Westover Hall who maintains the school's outdoor areas.

Elderly local resident who sits on his porch and watches the town.

Winged horses that serve as transportation for the quest group. Can fly great distances.

Becomes ill after being sabotaged, forcing the quest group to choose a replacement member.

History teacher at Westover Hall who teaches about military history and strategy.

College engineering professor leading a student group on a dam tour.

Businessman commuting to work who stops to watch the unusual military activity.

Various mortal residents of San Francisco who witness the supernatural battle but see it through...

Skilled archer among the hunters who specializes in silver arrows blessed by Artemis.

Clerk working at the Hoover Dam visitor center gift shop.

Head of security at Hoover Dam responsible for visitor safety.

Security guard at the Natural History Museum in Washington D.C. who patrols the exhibits.

Former military officer who supervises the dormitories at Westover Hall.

Local sheriff in Cloudcroft, New Mexico who investigates strange reports.

Fight alongside Nico in Hephaestus's junkyard, showing his growing power over the dead.

Skeleton warriors that spring from planted dragon teeth, summoned by children of Hades.

A massive bronze giant automaton guarding Hephaestus's junkyard. Ancient protector activated by...

Mortal taxi driver who gives Percy and Nico a ride, affected by the Mist to see normal explanations...

The mummified Oracle at Camp Half-Blood that gives prophecies. Speaks for the spirit of Delphi.

Local mechanic who fixes vehicles and reports seeing strange things.

Construction worker who sees military helicopters and reports it to his crew.

Tourist father visiting the museum with his family, taking photos of exhibits.

Tourist mother trying to navigate the museum with a map and brochure.

Security guards at Westover Hall who patrol the buildings and grounds during events.

Military school students at the dance, unaware of the supernatural drama unfolding around them.

Various wild animals encountered during the quest's journey through forests and wilderness areas.

A massive wild boar that becomes an unlikely ally, carrying the quest members on its back.

Storm spirits that attack the group during their journey. Servants of chaotic forces.

Dies from wounds inflicted by her father Atlas during the final battle. Her sacrifice helps save...