Son of Osivirius is an action packed, dystopian science fiction and fantasy novel by author Cathryn deVries. The story follows the journey of two siblings and their friendship with a pilot who crash-lands in their territory. deVries has built a rich and complex world on the planet Osivirius, with contrasts between the rigid, controlled and ordered colony, to the lush habitats and fascinating creatures of the rebel territory. The chapters alternate between Jayden and Nettle’s perspective, providing a rich and unique insight into the characters experiences and motivations. The romance is subtle and believable, unfolding naturally alongside Jayden’s internal struggle and moral awakening.

With superb world building, captivating characters, and a tender slow-burn romance, this is a must read for fans of dystopian science fiction and fantasy.

Son of Osivirius is a science fantasy novel set on the lush, dangerous planet of Osivirius, where electromagnetic “dead-zones” and rebellion complicate humanity’s survival. The story follows Jayden, a young pilot who crashes into a rebel stronghold, and Nettle, a fierce and distrustful woman who sees him as a threat. As Jayden struggles to heal and find a way back to his family, he becomes entangled in the rebels’ world of harmony with nature, flying cats called Masu, and a philosophy centered around balance. The narrative alternates between Jayden and Nettle, pulling readers into both perspectives and building a tale of survival, mistrust, slow-burning connection, and the search for peace in a world fractured by exploitation and greed.

I was hooked almost from the first page. The opening crash sequence was tense and immersive, and from there, the story barely let up. What stood out most to me was the vivid world-building. The descriptions of the valley, the rebels’ way of life, and especially the Masu, those awe-inspiring winged felines, gave me that rare feeling of stepping into a completely new world that still felt alive and believable. I loved the contrast between the sterile, suffocating colony and the lush, self-sustaining rebel enclave. It made me think hard about our own world and how we treat the natural environment, but it never felt preachy. Instead, the themes came through naturally in the characters’ choices and conflicts.

My feelings about the characters were complicated, and that made the experience all the richer. Nettle frustrated me at times with her hostility and refusal to soften, yet I understood why she was like that, and I respected her strength. Jayden, on the other hand, walked a tricky line between being sympathetic and being manipulative, and I often found myself both rooting for him and distrusting him. That tension gave the story its bite. There were also moments where I felt the romance threads were a bit predictable, but the emotional undercurrents of family loyalty, grief, and the fear of betrayal kept me engaged.

Son of Osivirius surprised me with its heart. Beneath the adventure and the danger, this is a story about belonging and trust, and how hard it is to let go of fear in order to live freely. I would recommend this book to readers who enjoy science fiction that balances action with deeper themes, especially fans of Avatar or The Left Hand of Darkness. It’s also a great pick for anyone who wants an adventure with strong characters, a lush setting, and deep ideas.

This was an amazing science fantasy novella! From the first page I was sucked in and invested in Jayden's story. I enjoyed his growing camaraderie with Flint and how he integrated into the valley, even if it was for the wrong reasons at first. I loved how he kept trying to crack the wall that Nettle had built, and watching their no-spice romance slowly build. The Masu creatures were a great touch, bringing hope and balance to the people and the world they had settled on. The world-building was exquisite, with wonderful descriptions that brought the story to life.

I really enjoyed reading Son of Osivirius by Cathryn deVries and raced through it in just a few days. I loved its uniqueness. It felt genuinely different from other books, especially in how the hero overcame the problem. I also liked the focus on living in community and in harmony with nature. That's something I think the world needs to be reminded of. Lots of people forget to do this--just enjoy what nature has to offer. This is a beautiful book.

My YA loving heart loved this book! Fantasy Sci Fi! The book started and just threw you straight into the world, not a soft fluffy cushy place to land either! I believe that teens would really enjoy this book the main characters are relatable, the story moves fast, there is no cliff hanger. Very light romance throughout.

I had the privilege of reading Son of Osirius as an ARC, and it completely pulled me in. The world feels expansive and alive, with vivid detail that never bogs down the story. The characters are complex and emotionally grounded, which makes the stakes hit even harder. And the flying cats? Majestic is the only word for them.

I’ve always been a huge fan of dystopian sci-fi and movies like James Cameron’s Avatar, so when I heard that Cathryn DeVries’ Son of Osivirius fit the bill, I had to see for myself. Sure enough, the book comes packed to the brim with gorgeously imagined locales, spirited characters, and a healthy dose of evil governments in need of overthrowing.

I absolutely loved this story! It’s full of adventure, loveable characters, and giant flying cats! But what I loved most was how this story gently challenges readers to see the world through different eyes, and the arc is simply beautiful! I highly recommend!

Cathryn deVries’s Son of Osivirius left me unexpectedly hopeful for our own world. In this sci-fi-fantasy-dystopian story, a group of rebels breaks away from the main population to learn how to heal the land ravaged by relentless mining and exploitation. As they learn to live in harmony with the earth, the dominant civilization continues its destructive path—until the rebels can no longer remain hidden. They must rise and fight for the world they call home.

DeVries’s characters are vibrant and authentic, and the world-building is both beautiful and immersive. My favourite YA trope—enemies to friends—is wonderfully realized through Flint, who sets off this transformation from the very first moment he discovers an enemy trespassing on their hidden sanctuary. I hope deVries continues writing in this world, because I’m completely hooked on the story, and curious about what comes next for Flint, Nettle, Jayden, and the huge flying cats. :)

Son of Osivirius stands out as a thoughtful piece of science fantasy that values character agency and ideas just as much as adventure. Cathryn deVries creates a setting that feels carefully considered, with themes of responsibility, connection to the natural world, and chosen family woven naturally into the narrative fabric. The characters feel purposeful and emotionally grounded, making their decisions and relationships engaging. What works especially well is the balance between introspection and forward momentum. The story invites reflection while still offering tension, discovery, and moments of wonder, giving readers space to connect with both the world and the people who inhabit it. There is a sincerity to the writing that feels earned, and the compassion running through the book gives it a distinctive voice within the genre. Son of Osivirius is an immersive and rewarding read for fans of science fantasy who appreciate rich worldbuilding, thoughtful themes, and characters who feel genuinely invested in the world they are trying to protect.

This was such a great novella! It was fast paced with short chapters. We get POVs from Jayden, a colonist, and Nettle, a rebel. I loved getting both of their perspectives. There is a romance subplot, and the development of that relationship felt organic.

There's some political power struggle, the balance of nature versus technology, and - perhaps my favorite - trying to find harmony and symbiosis with the apex predator species of the planet humanity is attempting to colonize. So much was packed deftly into this novella. Definitely recommend this for my sci-fi and fantasy friends. If romance is a deterrent for you, don't let it keep you from reading this. It's YA and there's zero spice.

I really, really enjoyed this book. I loved the cover and blurb of this book. I wasn't sure when I first started it. But as I read on, I couldn't put it down. I did like the writing style and the story. Loved the giant flying cats. I would love to see this on TV. The special effects would be amazing. I loved Jayden and Nettle. The chemistry between them. Wow. The action. I was surprised. I do hope there is more to come.

Wow this was incredible!

Right from the start we are swept into this wonderful world Osivirius. Cathryn deVries is magnificent and on point with the world building in this. I have a very vivid picture in my mind.

When Jayden a pilot for the Colony crashes near the Rebel out post he is not sure what they will do with him. Flint his saviour is adamant to heal him while his sister Nettle wishes for his death. We go on his healing journey with him and it is both sweet and endearing. I loved to learn of all the different foods and animals. Along with this was a deeper journey for Nettle of forgiveness and acceptance and for Jayden of understanding and belonging.

About halfway things started speeding up and I was feverishly trying to keep up, I couldn't put this down, hoping the whole way that they could salvage a relationship with the Colony. You will have to read the book to see what happens!

This was a great science fiction fantasy and would do amazing for any fans of the genre! Fast paced and full of meaning and trust me you will want to have your own Masu after this is done!

This was a really interesting read! For being a short book/novella, there was so much world building in it. The story really came alive for me. I would love to read another book set in this world!

Intense story with a great worldbuilding and may I say how much I love the Masu?? These wondrous creatures are just awesome and also the two main characters Jayden and Nettle.
Read it, you will not be disappointed.

Science Fiction is the genre I read the least of. Yet, I raced through this novella in only a couple of sittings and immediately looked up the author’s other books. This clearly shows how gripping this story is and also how fantastic the writing is.

I think I enjoyed this sci-fi story because it also had a touch of dystopian, fantasy and romance. The book begins with Jayden, on a mission from the colony, crash landing into the rebel’s camp. The story begins and continues to be action fuelled. The pace was kept fast, especially as time was moving on swiftly. The longer Jayden spent in the camp the more friendships he formed. There was a particularly sweet romance blossoming between Jayden and Nettle as well as a bromance with her brother Flint.

It was a high stakes, intense read. I was gripped by the storyline and I loved the descriptive writing. I could imagine this futuristic world and what a strange sight the Masu, giant flying cats, must be.

I absolutely enjoyed this book from start to finish. The plot, the stakes, the world building... Everything was exquisite.

This was a fun book to read. It had it all: adventure, romance, giant cats. Really enjoyed escaping into this story, and I'm always a sucker for romance. Not too long or too short. Love, love, love it. 10/10. Looking forward to the next thing the authors write.