Onyx Storm Review: Does Book Three Keep the Momentum?

Is Onyx Storm worth reading after Iron Flame? Here's an honest review of the third Empyrean book by Rebecca Yarros.

8/4/20263 min read

Onyx Storm Review: Does Book Three Keep the Momentum?

The third installment in Rebecca Yarros's Empyrean series arrived under enormous pressure — massive sales expectations and a fandom that had spent a year theorizing after Iron Flame's ending. Here's my honest take on whether Onyx Storm delivers. Read my Fourth Wing review and Iron Flame review first if you haven't, since spoilers for both are unavoidable here.

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Quick Answer

Yes, largely — this is a genuinely huge book in scope, expanding the war and the world significantly beyond the first two installments. I think it succeeds more as a bridge to the series' larger endgame than as a fully self-contained third act, which is worth knowing going in.

What It's About

Continuing directly from Iron Flame's ending, Violet and the surviving cadets face an escalating war that's expanded well beyond the confines of Basgiath War College. Without spoiling specifics, the conspiracy uncovered in the first two books widens into full-scale conflict, forcing Violet into a role with much higher stakes than survival within the college's walls.

My Honest Take

I think this book makes a clear choice to prioritize widening the war's scope over tightening the plot the way Fourth Wing's contained college setting allowed. That's not necessarily a flaw — a series has to expand eventually — but I found myself missing some of the claustrophobic, high-stakes tension that made the first book so immediately gripping.

The scale is genuinely impressive. If you wanted the conspiracy from the first two books to matter on a full geopolitical level, this book delivers that escalation convincingly, with real consequences that reshape the world beyond what either previous book established.

Violet's growth continues to feel earned. Her competence and authority have expanded believably across three books now, and I don't think this installment resets her development just to manufacture new vulnerability, which I appreciate as a consistent through-line.

The pacing is noticeably different from book one. Fourth Wing's tight, addictive momentum has fully given way to something more sprawling here — more characters, more political threads, more world to track. Readers who specifically loved book one's breathless pace should adjust expectations.

It reads more as a bridge than a self-contained arc. I think this book is clearly setting up the series' eventual endgame rather than delivering a fully satisfying resolution on its own terms — which makes sense structurally, but means the ending leaves genuinely major threads open rather than offering closure.

The relationship dynamics remain a strength. Despite the expanded scope, the central relationships — romantic and otherwise — retain the emotional weight that's carried the series from the start, even amid a much larger, more complicated plot.

What to Know Before You Start

You need full context from both previous books. This isn't a place to jump in — it assumes complete familiarity with Fourth Wing and Iron Flame's events.

It's a bridge book, not a conclusion. Don't expect the series' central conflicts to resolve here — this installment widens the story rather than closing it.

The tone continues to grow heavier. If Iron Flame felt more emotionally demanding than Fourth Wing, expect that trend to continue here.

Who Should Read This

  • Fans invested enough in the series to want the conspiracy to keep escalating

  • Readers prepared for a more sprawling, less tightly-contained structure than book one

  • Anyone willing to accept an open-ended bridge book rather than a self-contained resolution

Who Might Want to Pace Themselves

  • Readers who specifically loved book one's tight, contained pacing above all else

  • Anyone needing a satisfying resolution rather than an expanding, ongoing conflict

Amazon link: Onyx Storm by Rebecca Yarros

Frequently Asked Questions

Do I need to read Fourth Wing and Iron Flame first? Yes, essential — this book assumes full context from both previous installments.

Does this book resolve the series' central conflicts? No, it reads as a bridge toward a larger endgame rather than a self-contained resolution.

Is the pacing similar to Fourth Wing? Not quite — the scope has expanded significantly, trading some of book one's tight momentum for broader worldbuilding and political stakes.

Final Thoughts

Onyx Storm commits fully to expanding the Empyrean series' scope, delivering real consequences for the conspiracy set up across the first two books, even if that expansion costs some of the tight, breathless pacing that made Fourth Wing such an immediate hit. For invested fans ready to watch the story widen rather than close, it's a satisfying, if incomplete, next chapter.