Chapter 1: Lester (Apollo) / Still human; thanks for asking / Gods, I hate my life
Apollo, Meg, and the satyr Grover Underwood travel through the Labyrinth heading towards the American Midwest. Grover serves as their guide but struggles to navigate the ever-shifting maze. Apollo's powers have weakened further since the battle with Nero. They encounter blasts of supernatural fire in the tunnels and are pursued by strixes, deadly owl-like birds. Meg uses her Demeter powers and gardening seeds to block the creatures.
Chapter 2: Headless guys and gals / Not loving the Midwest vibe / Oh, look - a cheese ghost
Apollo, Meg, and Grover emerge from the Labyrinth in Indianapolis. They encounter blemmyae, headless creatures with faces in their chests, who are servants of the emperor Commodus. The trio must navigate the city while being pursued by these polite but deadly creatures.
Chapter 3: My last performance / Some old lady drops the mic / And kills everyone
Apollo is separated from Meg and Grover and teams up with Leo Valdez and Calypso, who arrived on Festus the bronze dragon. They encounter blemmyae in Indianapolis and are saved by a mysterious grey-haired woman named Emmie, a former Hunter of Artemis, who uses crossbow turrets to destroy the monsters. Emmie leads them to the Waystation, a magical refuge above Union Station.
Chapter 4: No building should be / A secret from Apollo / Or drop bricks on him
Apollo, Leo, and Calypso settle into the Waystation, where Emmie and her partner Josephine live with their adopted daughter Georgina. They learn the Waystation is a sentient building that provides refuge. Apollo discovers Commodus, the second Triumvirate emperor, controls Indianapolis and seeks the Cave of Trophonius, another ancient Oracle located nearby.
Chapter 5: Tell you a story? / Or I could just, like, pass out / And twitch on the couch
Apollo learns more about Commodus, his former lover from ancient Rome who became a cruel and deranged emperor. The memories of their relationship and Commodus's descent into madness haunt Apollo. He discovers Commodus plans a grand naming ceremony to rename Indianapolis after himself.
Chapter 6: Oh, Magic 8 Ball / Epic fail at prophecies / Leo's ear's on fire
Apollo and his companions plan their strategy against Commodus. Leo works on repairing Festus while Calypso trains in basic combat, having lost her immortal powers. Apollo receives cryptic guidance from the ghost Agamethus, Trophonius's brother, who communicates through a Magic 8 Ball.
Chapter 7: I chopped those onions / With my own ex-godly hands / You'd better eat them
Daily life at the Waystation continues as Apollo helps with chores and preparations. He bonds with the inhabitants and reflects on family dynamics between Emmie, Josephine, and young Georgina, who has been touched by the Oracle's madness.
Chapter 8: Lovebirds arguing / Trouble in Elysium? / I'll just scrum these plates
Tensions rise between Leo and Calypso as they adjust to mortal life together. Apollo observes their relationship dynamics and reflects on his own romantic failures. Meanwhile, intelligence gathering about Commodus's arena and plans continues.
Chapter 9: Of course it's a trap / With her, it always is one / Trappy McTrapface
Apollo and his allies infiltrate Commodus's operations. They discover the emperor has captured exotic creatures for his arena spectacles and is holding prisoners, possibly including missing demigods.
Chapter 10: Scrubbing toilets now / At least there's a great reward / Leftover tofu
Apollo continues his undercover work at Commodus's facilities, doing menial tasks to avoid detection. He gathers information about the emperor's plans and the layout of his stronghold.
Chapter 11: Four beheaded dudes / Are too much for one nightmare / Why me? Sob. Sob. Sob.
Apollo has disturbing nightmares about the Triumvirate's schemes and Commodus's growing power. The visions hint at the broader plan to control all the Oracles and the danger facing multiple demigod camps.
Chapter 12: I sing of taters! / Chili, sweet potato, blue! / Why? Ask my arrow
Apollo discovers his archery abilities fluctuate unpredictably. He trains with magical arrows and begins to understand how to channel brief bursts of divine power. His Arrow of Dodona provides cryptic Shakespearean-English guidance.
Chapter 13: Fast-food restaurant / My life goal is realized / Any fries with that?
Apollo, Leo, and Calypso go on a reconnaissance mission through Indianapolis, learning more about Commodus's control over the city and his preparations for the naming ceremony.
Chapter 14: Yeah, we got the skills / Fake hexes and shooting feet / Teach you 'bout pancakes
Apollo and his companions prepare disguises and infiltration plans. They learn more about Commodus's arena where he plans to publicly execute prisoners and perform gladiatorial spectacles.
Chapter 15: Drivin' the green train / I'm all like, Choo-choo! Choo-choo! / Can't catch me! - Oh, poop!
Apollo and his allies make their move against Commodus's stronghold. They navigate through the emperor's territory using stealth and Leo's mechanical skills.
Chapter 16: Son of a Midas / You, sir, are a stupid-head / Here, have an ostrich
Apollo confronts Lityerses, the son of King Midas and a swordsman working for the Triumvirate. He is a child of Demeter who calls himself the Reaper of Men. Just as Lit prepares to kill Apollo, Meg McCaffrey appears and blocks his strike with her golden scimitars, saving Apollo's life and revealing she has returned to his side.
Chapter 17: To the Waystation / Meg McCaffrey eats my bread / I cry godly tears
Apollo arrives at the Waystation with Meg. She has rejoined his quest after fleeing from Nero. The group prepares to face Commodus's forces, and Meg begins working with the others to plan their assault on the emperor's stronghold.
Chapter 18: My dear Commodus / Commode is named after you / Hail, Toilet Caesar
Apollo recalls his ancient history with Commodus, who was once his lover in Rome. The memories reveal how Commodus descended from a reasonable young man into a megalomaniacal tyrant, and how Apollo ultimately had to arrange his assassination.
Chapter 19: Call me Narcissus / Today I'll be your trainer / I'll also kill you
The group trains and prepares for the confrontation with Commodus. Calypso discovers she may retain traces of her former magic. Apollo and Meg strengthen their bond, and the quest to reach the Cave of Trophonius takes shape.
Chapter 20: Pedaling in style / Leg irons are fashionable / Cue the screaming god
Apollo and his companions journey towards the Cave of Trophonius. They face various obstacles and dangers along the way, with Apollo's weakening powers making the journey increasingly perilous.