The former Greek god of the sun, music, prophecy, and poetry is trapped in the mortal body of an acne-prone teenager named Lester Papadopoulos. Stripped of his divine powers by Zeus, he serves as Meg's mortal servant while attempting to restore the Oracles. He retains his godly ego but struggles with feelings of helplessness and guilt over his past mistakes.

A 12-year-old demigod daughter of Demeter who commands Apollo's service. She dresses in brightly colored clothes, wears rhinestone-studded glasses, and possesses immense power over plants and seeds. Her traumatic past under the control of the emperor Nero has left her guarded, but she shows fierce loyalty to her friends.

The son of the Roman god Jupiter who previously survived a war against the Earth goddess. He attends a boarding school in Southern California where he designs a temple project to honor forgotten deities. He carries the heavy burden of a recent prophecy and attempts to shoulder dangerous responsibilities alone.

A demigod daughter of Aphrodite who uses a Cherokee blowgun and a magical dagger named Katoptris. She possesses charmspeak, which allows her to persuade others with her voice. Dealing with her father's recent financial ruin, she struggles to connect with her Cherokee heritage while preparing to relocate to Oklahoma.

A satyr who serves as a guide for Apollo and Meg through the perilous maze. He wears modified sneakers to hide his hooves and uses panpipes to play magic-infused music. As the Lord of the Wild, he acts as a protector for nature spirits and deeply feels the environmental destruction ravaging Southern California.

A ruthless Roman emperor who has ascended to the status of a minor god. Operating under the title "Neos Helios", he commands a vast fleet of luxury yachts docked in Santa Barbara. He possesses a cruel, arrogant demeanor and plans to absorb the remaining essence of two sun deities to secure absolute power.

An ancient sorceress who works alongside Caligula in the burning maze. She harnesses the residual anger of a faded Titan to fuel the unquenchable fires plaguing the region. She possesses extensive knowledge of poisons and dark magic.

A talking white horse who once belonged to Caligula in ancient times and now serves as his primary enforcer. He harbors his own ambitions for an equine revolution while managing the emperor's guards.

An ancient Oracle blessed by Apollo who communicates exclusively through crossword-puzzle clues. She is currently imprisoned at the center of the maze by Caligula, forced to endure scorching conditions while awaiting rescue.

A combative satyr who drives a Pinto and actively encourages physical fitness. He assists Grover and Apollo during an ambush, utilizing his martial arts skills and musical abilities.

A cloud nymph who previously worked for the McLean family. She currently seeks refuge with the desert dryads while caring for her infant child.

A famous movie star and Piper's father. He recently lost his wealth and career due to the targeted financial attacks of a mysterious corporation, forcing him to move to an ancestral allotment in Oklahoma.

A seven-foot-tall, bald store manager who operates a front for the emperor. He commands an army of automatons and seeks to capture Apollo to regain favor with his master.

A botanist and descendant of an ancient Greek king. He built the sanctuary of Aeithales and prepared seven magical seeds before being forced to flee his home.

A large, fur-faced creature known as a pandos who serves as a guard on Caligula's yachts. Unlike his peers, he lacks interest in combat and desperately wishes to learn how to play music.

The ancient Titan of the sun whose fading memory generated deep resentment. His lingering anger and essence are currently harnessed by dark magic to fuel the unquenchable fires within the Labyrinth.

A desert dryad with a prickly personality who takes shelter in the ruins of Meg's childhood home. She fiercely distrusts outsiders but defends her fellow nature spirits.

A soothing, gentle desert dryad who provides medical care and comfort to injured nature spirits and weary travelers arriving at the sanctuary.

A dryad connected to the Joshua trees of the Mojave Desert. He monitors the sanctuary and works alongside the other plants to survive the unnatural drought.

A magical, sentient weapon that speaks directly into Apollo's mind using Shakespearean English. It offers vital clues and navigational advice, though its pedantic tone frequently annoys its wielder.

A nature spirit who participated in a search party ordered by Grover. She barely survives a magical attack in the Labyrinth and provides a vague warning about a dangerous sorceress.

A dryad sent to investigate the origins of the subterranean fires. She suffers critical injuries from encounters with the maze's guardians.

A senior pandos who acts as a ship commander in Caligula's luxury fleet. He displays unwavering loyalty to the emperor and dismisses any attempts at negotiation or bribery.

A pandos guard serving under Amax who attempts to detain the demigod intruders during their infiltration of the luxury fleet.

One of the fur-faced pandai tasked with securing the emperor's vessels. He fights against the demigod strike team during their rescue mission.