Son of Osivirius
About
Fast-paced, emotional, clean slow-burn enemies-to-lovers romance, mysterious powers, and themes of hope, identity, loyalty, and sacrifice. For readers who enjoy stories like Avatar. It's science fiction that balances action with deeper themes.
Jayden wants to do three things: find the rebel base, collect his reward, and never once let himself care.
Dispatched to locate a rebel settlement on the electromagnetically hostile world of Osivirius, Jayden Seymour crashes instead into a valley that should not exist: biodynamic orchards, hand-forged tools, and a society where no one is above serving the next meal or standing the next watch. This is not a rebel cell. It is a living argument against everything the colony was built to be.
But it’s the Masu that make the argument impossible to dismiss. Flying cats the size of small aircraft, they share a fungal mind-link with humans that opens up a wordless exchange no colonial education prepared him for. They do not ask to be trusted. They show you what trust feels like.
As the slow architecture of suspicion between Jayden and the woman determined to despise him begins to shift, so does everything he thought his life was for, and two people who built their entire existence around protecting one person slowly learn that the people most in need of protection might be each other. The cats have already decided, the only question left is whether Jayden has the courage to agree.
For fans of James Cameron’s Avatar and the ecological richness of Ursula K. Le Guin, this hopeful, slow-burn science fiction novel delivers lush alien world-building and a romance forged in shared grief rather than manufactured tension. What is at stake is not survival, but something far harder: the courage to choose a life that actually means something. This is soft science fiction at its most hopeful, with a slow-burn romance at its heart and giant flying cats who do not ask for your loyalty so much as remind you what it feels like to be whole.
If you've just finished Project Hail Mary and want another story featuring a human/alien friendship, this book might be just what you're looking for.
2026 Readers Favorite Winner (Short Story/Novella Category)
Wondering whether this story is right for you? Read the full “Is This Book for You?” guide.
Want to meet the characters? You can do so on the "Meet the Characters" page.
Want to know more about the Masu? You can find out all about them on the "Meet the Masu" page.
Interested in themes and tropes? Check out the "Themes and Tropes in Son of Osivirius" page.
Character Art by @alfibunneni
READ THE FIRST THREE CHAPTERS HERE.
Find BOOK CLUB and EDUCATORS GUIDES here.
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Exclusive Illustrated Edition (not available at retailers) Check it out below!
ABOUT THE ILLUSTRATED EDITION
You get:
Gorgeous two page chapter headers
Character art of the five main characters
Six botanical art pages hand-drawn by my youngest daughter
Scene art by my eldest daughter
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ENDORSEMENTS
“A lushly imagined, and hopeful serving of adventure filled with heart, humanity and flying cats. I loved it!” — Trent Jamieson, award-winning author of Stone Road, Day Boy, the Death Works Series, and the Nightbound Land Duology
“Delicious worldbuilding and characters that sparkle with agency. Son of Osivirius deftly highlights the importance of the natural world and humanity’s place within it. Cathryn DeVries weaves a brilliant tale.” — Pamela Jeffs, Aurealis Award winner and author of Wilder
“I adored this story from start to finish. A gripping plot, believable characters, and a richly immersive world that overflows with imagination and compassion.” –Kylie Chan, best-selling author of the Dark Heavens series and the Dragon Empire series.
EDITORIAL REVIEWS
⭐⭐⭐⭐⭐ - Literary Titan. Read the review
⭐⭐⭐⭐⭐ - Reader's Favourite. Read the review
⭐⭐⭐⭐⭐ - Reader's Choice. Read the review
Praise for this book
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.
Cathryn deVries has written one of the best, if not THE best dystopian sci-fi fantasy novellas I've read in a very long time. Son of Osivirius is world-building done right, with exceptional characterizations of protagonists, antagonists, and the fantastic Masu flying cats. I can't recall if I've ever read a story in which the leading characters provide first-person accounts in alternating chapters, the effect of which is to give exceptional clarity into the characters' thoughts, emotions, conflicts, and decisions. The slow romantic development between Jayden and Nettle, Jayden's struggle to decide whether to escape the rebel community and return to his family, his feelings for Nettle, the rebel community, and his own amazing Masu partner, Shana, are true to life in their depth of emotion and in the associated real-life, everyday experiences that require hard decisions among competitive choices.
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.
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.
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.