Originally published in 2014, The Blood of Olympus is the fifth and final book in Rick Riordan’s young adult fantasy series The Heroes of Olympus, inspired by Greek and Roman mythologies. The series follows seven demigods—children of one divine and one mortal parent—as they try to stop the earth goddess, Gaea, from rising to power. The novel won several awards, including the Goodreads Choice Award for Best Middle Grade and Children’s Book of 2014. The book explores themes of reconciliation, self-acceptance, and leadership.

This study guide refers to the Nook eBook published in 2015.

Plot Summary

The Blood of Olympus follows two quests—which converge at the novel’s end—from the third-person limited omniscient perspectives of five demigods: Jason, Reyna, Piper, Nico, and Leo. Seven travel aboard the Argo II to the Acropolis in Athens, Greece, to try to stop the ceremony to wake Gaea and overthrow the Olympians. These seven include Piper, Percy, and Annabeth, who are Greek, and Frank, Hazel, and Jason, who are Roman (though Jason is conflicted over which camp he belongs in). The second quest, led by Roman praetor Reyna—accompanied by Nico and Coach Hedge—is to deliver the Athena Parthenos statue to Camp Half-Blood as a peace offering from the Romans to the Greeks. In Reyna’s absence, Octavian, the Roman augur at Camp Jupiter, seizes power and plans to attack Camp Half-Blood. They must make it back in time to save Camp Half-Blood and heal the rift between the Greeks and the Romans.

As the novel opens, they arrive in Ithaca to gather information about the obstacles ahead. There, spirits, monsters, and mortals allied with Gaea overrun the palace of Odysseus. Jason confronts his mother, who abandoned him and has become a mania, and wards her off but is injured. After the group fights their way out of Ithaca, Juno advises them to visit Nike in Olympia and Apollo and Artemis on Delos. On the way, Leo ponders how to return to Calypso on her island, Ogygia. In Olympia, they capture Nike, the goddess of victory, who warns that one of them will die battling Gaea—and the physician’s cure won’t save them. Next, they stop at the port of Pylos, where Frank’s ancestors provide the poison to brew the physician’s cure, advising him to seek a statue of Ares in Sparta. Annabeth and Piper confront the statue, which radiates and amplifies fear. The inability to use reason overwhelms Annabeth, but Piper embraces and overcomes her emotions. She connects with her divine brothers, Fear and Panic (children of Ares and Aphrodite), delivering herself and Annabeth to safety. En route to Delos, the Argo II is battered by a ferocious storm. Percy and Jason investigate the ocean’s depths for the cause, Jason encasing himself in a storm spirit; they discover that the goddess Kymopoleia conjured the storm on Gaea’s behalf. Jason convinces her to switch sides by promising to build temples and shrines in her honor. She advises him to remember how the god Ouranos was overcome.

On Delos, Leo leads the search for Apollo and Artemis, with Hazel and Frank’s help. Leo has spoken with Nike and wants Apollo’s opinion on an idea. While conversing with Apollo, Nico invents a musical instrument that he offers the god of music in exchange for the physician’s cure. Apollo provides a necessary ingredient and sends the demigods to Asclepius, as only he can brew the potion. Piper, Jason, and Leo lead the mission, and Piper uses charmspeak to convince the physician, who is reluctant, having been severely punished for previously using it. After they obtain the cure, Leo—aiming to ensure that the war with Gaea and her monstrous forces ends—pretends to give it to Piper for safekeeping but instead hides it in the ventilator line of the Argo II engine. In Athens, the city’s founder and first king, Kekrops, a part man and part snake gemini, promises the demigods safe passage through his underground lair, but Piper charmspeaks him into revealing that his promise is a trap. Using her voice, she controls him, and he takes her, Annabeth, and Jason safely to the Acropolis. Frank transforms into a swarm of bees and arrives by air, and the others arrive later in the Argo II. In the fight with Gaea’s monsters, Annabeth is injured, and Percy gets a bloody nose. When their blood—the blood of Olympus—hits the stones of the Parthenon, Gaea wakes. The gods descend from Olympus to join the battle, fighting alongside their demigod children to defeat the giants, but they still must contend with Gaea’s awakening. Zeus sends the demigods on the Argo II back to Camp Half-Blood.

The parallel quest of Reyna, Nico, and Coach Hedge to deliver the Athena Parthenos from Rome to Greece begins in Pompeii. Nico transports them via his ability to travel long distances through shadows, but shadow-traveling takes a toll, threatening to turn him into a shadow himself. Reyna lends him her power, thus gaining insight into his loneliness and pain, and grows increasingly protective of him. While they rest, waiting for darkness to make their next shadow-jump, Reyna has a nightmare about Octavian preparing to march on Camp Half-Blood. That night, the ghosts of Pompeii attack, but the demigods defeat them and make their next jump. They land in Portugal, where Hades appears to Nico, warning him that Gaea’s hunter Orion has been sent to kill them—and that they can’t defeat him; they must outrun him. As they wait anxiously for nightfall, the werewolf Lycaon, Orion’s assistant, arrives with his wolves. Nico stabs him, using his melting shadow to shadow-travel the group and statue to safety. They land on a cruise ship and then in Reyna’s home of Old San Juan, Puerto Rico, where the Hunters of Artemis abduct her and take her to the Amazon queen Hylla, her sister. The Hunters and Amazons, working together to destroy Orion, redirected Nico’s jump to lure Orion to them. He attacks and kills many Amazons, destroying their headquarters, but Reyna, Nico, and Hedge escape with the statue.

Nico shadow-jumps them to Buford, South Carolina. He asks Reyna about her past, and she reveals that her mother, Bellona, a Roman war goddess, was her family’s patron for generations. She and Reyna’s father, a soldier, fell in love, but her father, obsessed with war, became a mania because of post-traumatic stress disorder and physical wounds from serving in Iraq. Reyna tearfully admits that she accidentally killed her father one night after he attacked Hylla. Nico insists that Reyna is innocent, since her father was already a wraith, but the Romans consider fratricide a grave crime; if they knew what she’d done, they’d execute her. As she makes her confession, Roman legionnaire Bryce Lawrence appears, arresting her. Bryce’s cruelty enrages Nico, and he destroys him, unsettling Reyna and Hedge. Exhausted after killing Bryce, Nico falls into a shadow coma for three days, almost becoming a ghost. He’s surprised that Reyna and Hedge nurse him to health, thinking his actions must have repulsed them, but they reiterate that he’s their friend. Nico can’t survive another jump, however, and Hedge has arranged for winged horses to transport them and the statue back to Camp Half-Blood. When they arrive, the Roman attack is imminent, but not all the Romans agree with Octavian’s actions. Reyna sends Nico and Hedge back to camp to help the sympathetic Romans sabotage Roman weapons. Orion finds Reyna, but she kills him with the help of the Athena Parthenos and her mother, Bellona. Nico connects with Greek demigod Will to conduct the sabotage operations, but Octavian catches them. As he orders the Roman forces to attack, Reyna flies in with the statue and urges the Greeks and Romans to join forces to fight Gaea, who is now awake and rising from the earth.

The two quests converge during the war at Camp Half-Blood as the demigods on the Argo II arrive and join the fight. Leo flies his bronze dragon Festus, whom he has restored, into battle. The dragon grabs Gaea, lifting her off the earth, the source of her strength, and Piper charmspeaks Gaea back to sleep. As Leo sends Jason and Piper away so that he can vaporize Gaea without harming them, Octavian fires his onager, unaware that his robes are tangled in the trigger, and is launched into the sky in a fireball that collides with Festus. Gaea has been destroyed, but so has Leo. The Roman and Greek camps mourn together as they fought together. The demigods blame themselves for Leo taking on the dangerous plan—but the final chapter reveals that Leo programmed Festus to inject him with the physician’s cure. Leo finds his way back to Ogygia, and he and Calypso ride Festus away from the island.