Onyx Storm by Rebecca Yarros: A Review

By the time a series has sold this many copies, review math changes. Nobody needs to be told that Rebecca Yarros writes dragons, sex, and grief better than almost anyone currently doing romantasy in mass paperback. What they need to know is whether book three of The Empyrean survives the notorious "middle book slump," and whether it's worth the eighteen-month wait since Iron Flame left readers with one of the more brutal cliffhangers in recent memory.

Our panel read Onyx Storm the way most of its actual audience will: in two or three sittings, late at night, with a highlighter for the lines that will inevitably end up on someone's Instagram grid. Nine of twelve panelists finished it in under 48 hours. That is not a coincidence — it's the entire design of the book.

What Actually Happens (Spoiler-Light)

Violet Sorrengail survives Iron Flame's ending, but survival is about all she gets. Onyx Storm picks up with the war against the venin no longer a background threat but the entire plot, and Yarros widens the map considerably — new territory, new political players, and a body count that makes clear nobody's safety armor from the first two books still applies. The signature Basgiath War College setting takes a back seat for long stretches, which several panelists found disorienting at first and then appreciated once the new locations started paying off.

The relationship dynamics that made the first two books addictive are present but recalibrated — this is less will-they-won't-they and more how-do-two-people-stay-together-when-the-world-is-ending, which is a harder thing to write and mostly lands. The banter is thinner than Fourth Wing's; the stakes are heavier than Iron Flame's. It reads like a book aware it's the middle of something bigger, for better and worse.

Where the Pacing Actually Slows Down

Every panelist who'd read the first two books flagged the same stretch: roughly the back third, once the major set-piece action sequence resolves and the book downshifts into political maneuvering and relationship repair. It's not bad writing — it's necessary connective tissue for a series that clearly has at least two more books planned — but it's a noticeably different reading speed than the first 300 pages, and three panelists admitted to skimming dialogue-heavy chapters to get back to the plot.

That said, nobody on the panel called it a slog, and the last 60 pages reset the pace hard enough that two panelists reported staying up past 2 a.m. specifically because they'd told themselves they'd stop at the chapter break and then didn't.

We also asked panelists to flag any moment where they felt the book was retreading ground from the first two installments rather than advancing it — a common failure mode in long fantasy series once the initial premise has been fully explored. Only two panelists flagged any such moments, both in early chapters before the plot widens past the academy setting, which suggests Yarros is managing series fatigue better than most authors attempting a fourth-plus installment in a popular series.

Who This Book Is (and Isn't) For

If you loved Fourth Wing for the dragon-riding academy setting specifically, Onyx Storm's wider war-story scope will feel like a departure — not a bad one, but a real tonal shift. If you loved it for Violet and Xaden's relationship under pressure, this book gives you more of exactly that, just under worse pressure. New readers should not start here; this is very much a middle book and assumes total familiarity with the first two.

Panelists who came to this book as parents specifically flagged the content notes as worth taking seriously — this is not YA despite the age of its protagonist, and the violence in particular escalates past what either of the first two books depicted. If you're recommending this series to a younger reader based on the first book's marketing, read Onyx Storm yourself first.

The Details

How It Stacks Up Against the First Two Books

Panelists who ranked all three books put Fourth Wing first for pure readability — it's the tightest, funniest, and most propulsive of the three, in large part because it only has to establish stakes, not sustain them across a widening war. Iron Flame ranked second for most panelists specifically because of its ending, which several called the most effective cliffhanger they'd read in the genre in years. Onyx Storm ranked third on pure pacing but first on "emotional maturity" — panelists consistently used some version of the phrase "it feels like the characters are actually being changed by what's happening to them," rather than resetting to status quo between books the way a lot of long-running series do.

That ranking shift matters for anyone deciding whether to keep reading past book two. If you loved Fourth Wing for its speed and are hoping Onyx Storm replicates that exactly, temper expectations — this is a book about consequences, and consequences slow things down by design. If you loved the characters more than the pace, book three delivers the most character growth of the series so far.

Common Questions About Onyx Storm

Do I need to re-read the first two books first? Given the eighteen-month gap since Iron Flame, we'd recommend at least a plot-summary refresher — Yarros does some recapping in the early chapters, but not enough to fully reorient a reader who's forgotten the specifics of who betrayed whom.

Is this the last book in the series? No — Onyx Storm ends with clear setup for at least one more installment, and several plot threads are deliberately left open rather than resolved.

Is the romance still central, or does the war take over? Both, though the balance shifts. The relationship material is present throughout, but it's tested by circumstance rather than driven by will-they-won't-they tension the way earlier books were — a natural progression for a couple that's already committed to each other, but a different reading experience than book one.

The Verdict

We gave Onyx Storm an 8.7 out of 10. It's not the tightest book in the series, and the back-third pacing keeps it from matching Fourth Wing's propulsive first read — but it takes real risks with its cast and its world instead of coasting on the first book's momentum, and nine of twelve panelists said they'd re-read it before the next installment drops. For readers already invested in The Empyrean, this is a must-read, pacing dip and all. If you haven't started the series, don't begin here — go to our romance and romantasy roundup for where else to start.

One last note for anyone deciding whether to buy in physical, ebook, or audiobook format: our panelists who listened to the audiobook consistently rated the dragon-bond telepathy sequences and battle scenes higher than those who read the physical or digital text, crediting the narration with adding tension the page alone doesn't fully deliver. If you've already read the first two books in print and are on the fence about switching formats for book three, this is one series where the audio production genuinely earns the switch.