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Some wounds never heal. . .

It’s been a few months since Casper Bell saved Novilem from crumbling under the pressure of revolution. The dust hasn’t settled, and neither has his nerves. A strange sickness is spreading in the city, and Casper is having visions about the tower Jacob sent to the Surface. Helix convinces him to bring his concerns to the Estellar council, but Helix’s trust in the system backfires. They send the pair to the last place Casper wants to Earth.

Casper’s past is right where he left it and corrupted aether still creeps on the streets of Chicago. When they find someone who is aether sick, it is clear they haven’t finished uncovering the council’s secrets.

With their friends and family falling sick, the fragile peace in Novilem collapsing, and the council ready to abandon the home they have fought so hard to protect, Casper and Helix must confront their inner darkness before Novilem is lost forever.

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326 pages, Kindle Edition

Published July 7, 2025

35 people are currently reading
128 people want to read

About the author

Craig Montgomery

2 books126 followers

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Displaying 1 - 19 of 19 reviews
Profile Image for Kerie.
84 reviews30 followers
July 8, 2025
A Sky So Hollow, the second and final installment in the stardust duology, was, to put it simply, WONDERFUL. Although book one ended with resolved enough plot lines to not necessarily warrant a second book, I’m so glad we got one as this story, despite its own high stakes plot to defeat the villain and restore the people’s voice to tables of power, felt like a deeper exploration of its characters and their emotional underpinnings. Casper’s emotional journey and character development was a standout for me and featured a beautifully realistic portrayal of PTSD and the process of healing from childhood wounds. As a SFF reading trauma therapist this just REALLY hit a sweet spot for me.
And can I just say - I loved seeing more from our bad ass sidekick mom character, Talleah. I’ll be thinking about sweet Casper and his friends for a long time.

Found family, queer love, realistically portrayed mental health rep that made me cry, and a bad ass mom sidekick, in SPACE?!

I wanted to immediately start over and read it all over again.
Profile Image for KMart Vet.
1,548 reviews82 followers
July 4, 2025
4.5/5 stars, rounded up because of how seen and happy it made me.

A strong finale that isn’t afraid to challenge its characters, but in ways that feel thoughtful and completely earned.

I loved Helix and Casper together, but that didn’t mean their journey was over. There’s still so much emotional growth (both personal and relationship) packed into this story. The conflict between them, especially around how they process and express emotion, really hit home for me. It’s rare that I feel seen like that in a book, but wow. You didn't have to come for me like that, Craig. That argument? Brutal and honest and real. And hits a little close to home. Thank you, ✨trauma✨

Compared to the first book, this one is way less political and far more personal. At times, they weirdly don’t always feel like two halves of the same duology? I don't dislike it, but it doesn't feel completely cohesive, if I'm splitting hairs. I love both of these books for different reasons.

The monsters are grotesque and deeply cool (shoutout to body horror fans), and they feel like a physical manifestation of rage, wild and unrelenting and very symbolic. That allegory worked so well for me. The world-building escalates fast, and while the politics of Novilem take a bit of a backseat, the stakes are still sky high. There are great themes threaded throughout: oppression, privilege, grief, and how messy relationships can be, even (especially) when love is involved.

Also, as someone who lives in Chicago, the Earth scenes (the Christmasing!!) were so vivid and personal. I could SEE it. The quiet intimacy of those scenes really balanced out the rest.

All in all, this duology stuck the landing. Uneven in some ways, but heartfelt, intense, and full of love, monsters, and very human mess.

I appreciate the complimentary copy from the author and this review is voluntary. All opinions are my own.
Profile Image for José Orlando.
140 reviews66 followers
July 26, 2025
“A Sky So Hollow” by Craig Montgomery is everything I wanted in a sequel and somehow even more. I already loved “A Circle of Stars”, but this book took it to another level. Since the world was so richly established in the first one, this story jumps straight into the action, giving us more time to dive deeper into the characters we’ve grown attached to. Casper’s journey hit me hard. His trauma after being cast out by his family for being gay is finally given the space and weight it deserves, especially in his complicated relationship with his father. That emotional depth, paired with the tension and vulnerability in Casper and Helix’s relationship, made this feel so much more intimate and raw. Their bond is tested in real ways, but they’re still their charming, lovable selves, and I was rooting for them the entire time.

What I also loved was how this book expanded the lore of the aether and its astrological magic system in such a fascinating way. The stakes feel higher, the atmosphere a little darker, but there’s something oddly cozy and comforting about it too. Maybe it’s the way the book blends action and introspection so well, reminding us that saving the world starts with healing yourself. The pacing was tight, the plot was exciting, and the monsters and magic were all elevated in this installment. Casper’s arc comes to a truly satisfying conclusion, and by the end, I felt like I’d gone on a personal journey right alongside him. This was a beautiful, bold, and heartfelt story and easily one of my favorite reads of the year.
9 reviews
July 22, 2025
As someone who finished book one just yesterday—but bought book two halfway through the first—I can say this series quickly captured my heart.

Watching Casper embrace his emotions and begin to heal from his past was a cathartic experience. Seeing him reframe the cruelty of others as their loss—and recognize his own worth—felt deeply personal and profoundly relatable, especially for queer youth navigating identity and self-acceptance.

Helix, ever the level-headed and emotionally grounded counterpart, also reveals his own vulnerabilities. His hesitation and fear surrounding his growing feelings for someone so guarded made his courage to move forward all the more impactful.

Their relationship felt organic—beautifully flawed, with highs and lows that only strengthened their bond. I appreciated that the romance wasn’t idealized but rather grounded in mutual growth and resilience.

That said, I did find myself wishing for more fleshing out of some finer details. This book leaned a bit more into Tal’s arc, which at times worked seamlessly, and at other times felt slightly out of sync with the main emotional beats.

I could easily see this series expanding—either as a trilogy or with a final novella—to tie up a few lingering questions: Do Casper and Helix live together? Get married? Do they all eventually master the counter aether? Is a new governing body established? What about the restoration of familial relationships? Perhaps these are superficial or just personal curiosities, but they left me hoping for more.

Still, A Sky So Hollow was a deeply moving and rewarding continuation, and I’m grateful to have taken the journey with these characters.
This entire review has been hidden because of spoilers.
Profile Image for S.
60 reviews5 followers
July 8, 2025
A Sky So Hollow is the conclusion to the Stardust Duology! I love this series so much. A Circle of Stars set up this beautiful world to explore, with Casper the Telos of Novelim, able to control all 12 houses of aether; and his boyfriend Helix, son of the high prietan Brissa who would do anything for their people; and Talleah, a mother who trying to claw a future out of the hard rock of Novelim for her family. The series is true sci-fi: exploring complex themes of trauma, politics, power, and the morality of governing, but it remains accessible and thrilling without being bogged down by the difficult ideas it explores.

Part of the reason for that is the high stakes plot, with the fate of Novelim and aether itself in the balance, and part of the reason is the narrative voices of the characters. Helix, Casper, and Talleah, are all so real with such strong voices, the story thrives through their perspectives. This one deals a lot with Casper’s inner trauma, Helix’s grief, and Talleah’s anger. Each character is more than just a vessel for their story. They are their story, they are rich and relatable depictions of how it feels to be human, even in space.

I laughed, I cried, I gasped, I crashed out in public. The things that are uncovered in this book hit so hard right now, and it manages to capture the struggle of existence, the struggle of humanity, of chaos and order, all in one incredible conclusion, while simultaneously offering hope in the darkness.

A Sky So Hollow is the perfect ending to a perfect series.
Profile Image for travis.
225 reviews31 followers
August 23, 2025
Very grateful this book had a summary and character index at the start because I fear I forgot a good amount from the first book. It felt like the start of this book was kind of at odds with the rest of it, or at the very least the whole "let's go back to earth and visit a gay bar and watch a drag queen with a name I don't think any queen would actually have" scene felt completely out of place. And then the guy who outed Casper was there and gets kicked out for it and the whole time I was like, okay does he not deserve his own growth? Is he not capable of change? What he did was wrong but there's no knowing what he went through... this is SUCH a weird, minor thing to focus on but it just felt like wrapping up certain things really quickly and obviously, when I'm not even sure if they needed to be wrapped up

I recognize the Earth part was to get Casper's dad in the mix and that was for his own emotional journey and healing, but even then that felt sort of stilted and awkward in the long run. It also opened up the question to me about why Earth in particular seems to be getting affected by the aether weirdness when they don't use it

Regarding Casper's healing journey:

Ultimately I still found myself enjoying the ride, even if the whole people turning into monsters and shit was kind of at odds with the overall YA vibe and nature of the story. There's definitely some interesting ideas and potential in this book, like the first, but again I think the execution left a lot to be desired
Profile Image for Brittany.
1,099 reviews37 followers
December 16, 2025
First things first, Craig is a close friend so this is unfortunately a biased review, but I am also not sorry about that because I love Craig’s writing so much.

I was SO happy to delve back into this fantastical/science fiction world of Ouranos and to be reunited with my favorite gays in space, Casper and Helix <3

I appreciated the dynamics and journey that Craig explores by placing Casper and his bigoted dad together, which is no easy feat. I was really proud of Casper’s growth and ability to stand strong in his convictions, even in the face of those who hate to see him stand tall and proud of himself.

The action is very fast-paced, especially towards the end, so I have no doubt that folks will be enticed to keep turning the pages to see how this intergalactic conflict resolves.

This upper YA fantasy completes the duology in such a satisfying, exciting, and swoon-worthy conclusion that I am confident readers will be sad to close the book. I would love to see this optioned and adapted for a television or film series — the found family would be so fun to follow, even after the events of this book are over :)
Profile Image for Stephanie (Gorelenore) Cover2CoverBlog.
1,410 reviews41 followers
Read
July 10, 2025
No real fault of the author - but my ARC would not stay downloaded on my Kindle and it was driving me insane. Any time I wanted to read it would act like it never downloaded and queue up to download... then after multiple clicks finally let me into the book.

...That compounded with the fact that I was not really that invested in the characters or story, put this in the DNF pile. I enjoyed the first one and think that this one just fell at the wrong time for me.

I made it 23% in. At that point in the plot - we had covered most of the things noted in the synopsis - Casper a hero but having visions, no one taking them seriously, Helix loooooves him, and they go to Chicago for a bit and have to bring someone back because they have Aether sickness. While it was flowing, I wasn't fully committed - sorry.

If you like a good sci-fi and are looking for some LGBTQ+ rep, this could be for you.
Profile Image for Taylor.
8 reviews1 follower
May 27, 2025
A topically poignant story of oppression and privilege, A Sky So Hollow brings us back to the magical world of Novilem in a brash yet tender follow-up story. Emotions run high as our main characters reconcile with the events of ACOS. ASSH delves deeply into the internal struggles of our protagonists Casper and Helix, showing more work needs to be done before our heroes can truly save their home.

Montgomery does a wonderful job further carving out the facets of his well-developed characters, while gripping the reader’s attention with high stakes, intense action sequences, and high concept magic system. I cannot recommend this duology enough.

I received an advance copy of this book from the author, and I am leaving this review voluntarily.
Author 4 books5 followers
June 12, 2025
The first book, A Circle of Stars, lives in my head rent-free, so when I was offered the honor and privilege of reading the 2nd book of the dualogy, A Sky So Hollow, I was over the moon! And it didn't disappoint!!
When I say run to get your copy, I mean run!
The author does a fantastic job of building on the foundation of Helix and Casper's relationship in a dynamic and real way while also balancing action and pacing! The emotional growth arcs (together and separately) are beautifully poignant while also staying true to the characters. *chef's kiss*

For all my annotators out there, get your highlighters ready. There are so many gems you'll want to keep coming back to.
Profile Image for Em .
30 reviews10 followers
July 6, 2025
This was a fantastic follow-up to A Circle of Stars. Craig Montgomery's writing style continues to be sharp and emotionally moving. The further world-building was crafted beautifully. As the story unfolded, I found myself surprised countless times, quite possibly shrieking out loud at some points. 🤭 Casper, Helix, and Talleah remain the focus of the story, but we got more in-depth character-building with several others as well. This conclusion to The Stardust Duology was incredibly clever, and I can't wait to see what Montgomery comes up with next.
Profile Image for Ryan Carrow.
441 reviews32 followers
September 1, 2025
4.2⭐️
0🌶️

Listened to the audiobook on Audible

I love when an author ties up loose ends.when he left Earth I was afraid we would not get resolution to the situation with his family. Thankfully we were brought back and allowed to get that closure to his abusive family. Also with Casper being able to power uppp. The author wanted to show some boundaries with relationships and did not want them to live together but he really hounded on it. The magic system kind of became back burner in this book which was sad because I love it.
This entire review has been hidden because of spoilers.
Profile Image for Gabby Zabek.
166 reviews
September 11, 2025
Question: Are we sure the story outline didn’t get published by mistake? Because this book was a solid 150 pages shorter than the first and the lack of depth and detail showed. The pacing was atrocious, I felt like I didn’t have a chance to care about a single plot point because we just moved on. Honestly so disappointing because if it would have been even better than the first book if it read like it.
23 reviews
May 25, 2025
Thank you to the author for providing me with an eARC. I really loved this duology. For me, this was such a unique take that I haven’t encountered before.
I fell in love with the characters in book one and love them even more now.
I’m so sad that this is the end but so glad I experienced it!
Profile Image for Michael.
382 reviews15 followers
July 8, 2025
Hollow, yes. The first one was cute if rough, but this is too much like listening to your friend describing their sessions with a new age life-coach-therapist.

Yes, we could all save the world if we all had magic-of-the-ancients psychedelic therapy.
Profile Image for Kyle Moncelle.
14 reviews5 followers
August 13, 2025
“None of us do anything alone...”

I was delighted to receive an advanced copy of “A Sky So Hollow,” and am leaving this spoiler-free review voluntarily.

A Sky So Hollow picks up shortly after the events of A Circle of Stars, reacquainting us with our reluctant and damaged chosen one, Casper, his politically ambitious yet sensitive paramour Helix and their prickly but caring friend Talleah. Their world is broken, left shattered after the events of the first book in the duology, compounded by the chillingly relatable spreading pandemic that is slowly eating its way through the population of Novillem.

In my mind, the best sequels are those that recontextualize what you already know, causing you to reflect and reexamine details with new information in mind. Montgomery does this exceptionally well! There are new elements introduced that heighten the (already quite high) stakes from the first volume, without making the story reliant on what came before. We learn more about the magic system, the world itself (as well as our world), the Novillem culture and even their ruling body. The scope is really sweeping without sacrificing an intimate feeling for the sake of epic-ness.

I was really surprised by Montgomery's willingness to get *messy* with these characters. In the first book, we learn a little about the emotional struggles each protagonist carries, but here we really dig deep and get to see how their sharp corners bump into each other. Possibly what I loved the most was the challenges to Casper and Helix's relationship. We're not in honeymoon territory any more, and both characters struggle with their respective traumas and how they rears their heads in their still budding relationship. Huge kudos to the author here, because it's not easy to make wounded characters feel vulnerable and relatable, but I found myself rooting for each of them in turn and feeling the depths of their pain.

Overall, Montgomery successfully avoids a sophomore slump here, delivering a thrilling, emotional and vulnerable story that balances character development, interpersonal relationships and exciting plot points while also making you rethink what you thought you knew from A Circle of Stars. My only major critique is that the story ends here!
Profile Image for Trish Skywalker.
1,085 reviews64 followers
July 30, 2025
This world Craig created absolutely blew my mind. A world built in a moon, where people have magic abilities based on astrological signs. And a very sweet romance between two absolutely beautiful young men.
I don’t want to give away too much of the plot because it would ruin both books, but this is a wild ride. Our MCs, Casper and Helix, are in the fight of their lives in this book: to save Novilem from evil forces. We see both men struggling with their past trauma, and while at first it seemed like something necessary for their relationship, it also becomes needed to save their world. There’s so much emotion and grief for them to deal with, but now it’s a matter of life and death.
Though there were so many moments when I didn’t know how they’d get through, I cheered for them with every page. If there’s any couple I’ve rooted for to get a well deserved HEA, it’s these two 💙.
Thank you Craig for giving us this wonderful world!
Profile Image for Drew Hill Drewbious.taste.
6 reviews
July 8, 2025
A fitting end to an epic story.

While I loved all of the delicious and complex world building that occurred in A Circle of Stars, it was exciting to get to dive deeper and live in the world of the story in book two. After the cataclysmic events at the end of book one, A Sky so Hollow picks up with Caspar and Helix finding their way in city that clings to a problematic past and faces a difficult future.

The main plot was exciting and the stakes were definitely high enough. While the main message of the importance of finding “balance” was a little predictable, it was captivating enough that it was still completely satisfying.

The relationship between Caspar and Helix was what really set this book apart for me. By the end of book one they were solidly together and had already confessed their love, which made exploring their dynamic in book two that much more enriching. Many readers hate the miscommunication trope because “everything would be fine if they would just talk to each other!!”, but in this book Caspar and Helix are completely open with each other and their relationship is still hard. Seeing the ways they communicate and make the effort to be there for each other while struggling with their own demons felt so heartening.

On its own I felt the pacing was great but looking at the duology as a whole it feels like some of the elements from book two could have been introduced in book one to give them proper time to marinate with the reader.

Overall this is an excellent read. It’s unique and compelling and combines many different ideas and themes in a fresh and exciting way. Would definitely recommend it to anyone who enjoys sci-fi/fantasy with empathetic and emotionally intelligent characters. (I received an early copy at no charge but my opinions are honest and my own.)
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