The Son of Neptune — Heroes of Olympus, Book 2

The Son of Neptune Review

The second Heroes of Olympus novel pulls off something genuinely difficult: it returns readers to Percy Jackson — arguably the most beloved protagonist in contemporary middle-grade fiction — without undercutting the new characters introduced in The Lost Hero. Percy wakes amnesiac at Camp Jupiter, the Roman demigod training ground in the hills above San Francisco, and the fish-out-of-water dynamic from the previous book is inverted. Now it is Percy who is the outsider, and the Roman camp’s rigid, hierarchical culture makes the contrast with Camp Half-Blood both comic and illuminating.

But the book’s greatest achievement is its two new supporting protagonists. Hazel Levesque, a daughter of Pluto raised in 1940s New Orleans and inexplicably alive in the present day, carries a backstory of unusual emotional weight for a series aimed at younger readers. Frank Zhang, an awkward Canadian son of Mars whose family bears a destiny tied to a burning piece of wood, is equally compelling — and his arc, which builds to a moment of sacrifice that redefines his character, is among the most affecting sequences Riordan has written.

The Alaskan quest — to the land beyond the gods’ reach, where Thanatos is chained and the giant Alcyoneus holds power — gives the novel genuine geographic and mythological scope. The Roman framework, with its emphasis on military virtue, duty, and honor, creates productive friction with Percy’s instinctive, empathy-driven heroism.

Reading Order

1. The Lightning Thief (Percy Jackson, Book 1)
2. The Last Olympian (Percy Jackson, Book 5)
3. The Lost Hero (Heroes of Olympus, Book 1)
4. The Son of Neptune (Heroes of Olympus, Book 2)
5. The Mark of Athena (Heroes of Olympus, Book 3)
6. The House of Hades (Heroes of Olympus, Book 4)
7. The Blood of Olympus (Heroes of Olympus, Book 5)

Reading Guides

• Rick Riordan Books in Order: Percy Jackson and All Series (2026)

Frank and Hazel as Hobb-Level Character Work

For a series aimed at middle-grade readers, Frank and Hazel carry unusually complex emotional histories. Hazel Levesque died in the 1940s, was brought back by her half-brother Nico di Angelo through his power over the dead, and carries guilt over a choice she made in her first life that she believes condemned the world she is now trying to protect. Her power — the ability to summon precious metals and gems from the earth — comes with a curse: the riches she summons bring disaster to those who take them.

Frank Zhang’s situation is equally precarious. His life is literally tied to a piece of wood that his grandmother keeps in a fireplace: while the wood burns, Frank lives. His mother died in combat in Afghanistan, his grandmother is the repository of a family destiny connected to the Roman god Mars, and his power — the ability to transform into any animal — is so dangerous that he has been afraid to use it.

These are not typical adventure-fiction backstories. Riordan asks his readers to hold alongside the quest action a genuine meditation on inherited guilt, the weight of family destiny, and the courage required to act when acting might cost you everything. Frank’s transformation in the novel’s climax is one of the most affecting sequences in the Heroes of Olympus series precisely because the reader has been made to understand exactly what it costs.

The Roman World Fully Realized

The Son of Neptune gives Camp Jupiter more depth than it received in glimpses through Jason’s memories in The Lost Hero. The Roman demigod community’s emphasis on military virtue, collective discipline, and duty to the legion creates a world that feels genuinely different from Camp Half-Blood — not inferior, but operating from different premises about what heroism means and what it requires. Percy, shaped by the Greek emphasis on individual excellence and emotional loyalty, is a productive outsider in this culture, and his friction with its expectations illuminates both.

The Roman Framework as Narrative Device

Riordan’s decision to use the Greek-Roman split as The Son of Neptune’s central structural tension was among his most inventive choices across the Heroes of Olympus series. Camp Jupiter operates on principles genuinely different from Camp Half-Blood — military hierarchy, collective discipline, the subordination of individual glory to the legion’s honor — and Percy’s disorientation within this system illuminates both camps in ways that neither could illuminate alone. The Roman emphasis on duty and collective virtue sits against the Greek emphasis on individual excellence and emotional loyalty, and Riordan refuses to adjudicate between them; both produce heroes, and both produce failures.

Percy’s instinctive empathy — the quality that has defined him since The Lightning Thief — creates productive friction with the Roman system’s expectations. He earns the legion’s respect not by conforming to its values but by demonstrating his own so completely that the camp is forced to accommodate them. This is a more nuanced argument about cultural integration than most middle-grade fiction attempts.

Frank and Hazel in the Broader Series

Frank Zhang and Hazel Levesque were developed for The Son of Neptune with unusual care, and they reward that care across the remaining three books of the Heroes of Olympus series. Frank’s power — the ability to transform into any animal — grows in scope and cost as the series progresses. His family destiny, tied to a piece of wood that his grandmother keeps from burning, provides the series with one of its most emotionally acute moments in the later volumes. Hazel’s ability to manipulate the Mist — developed from her curse of summoning precious metals — becomes a tactically essential skill in The House of Hades and The Blood of Olympus.

Riordan’s decision to build two new major characters with genuinely complex backstories, rather than simply relying on Percy’s return, is the structural choice that makes the Heroes of Olympus series work as more than a sequel. The series’ final volume, The Blood of Olympus, gives both Frank and Hazel conclusions commensurate with the investment the earlier books built, and The Son of Neptune is where that investment begins.