Son of Osivirius: A Science Fantasy Novella

by Cathryn deVries

176 pages, Hardcover

Expected publication February 17, 2026

About the author

Cathryn deVries is an award-winning fantasy and sci-fi author who explores themes of restorative justice, empowerment, connection with earth and spirit, and finding the true self in her work—all wrapped up in an epic package of immersive world-building and sweet romance. A former Air Force engineer and recovering perfectionist, she now home-schools her children, two of whom are on the autism spectrum. She and her family live in the Gold Coast Hinterland of Australia, where she enjoys living in a rainforest and pretending she’s an elf.

Reviews

[Norma · Rating 5 out of 5]

A wonderful read!

I enjoyed how the author wrote a vast new world similar to the world of Pandora but made it all her own. I love the Masu and wish I had one in real life.

I also enjoyed how Jayden and Nettle’s relationship grew along the way and how that helped them grow as characters.

[Stephen Hipkiss · Rating 5 out of 5]

Sci fi fans put this on your TBR, this is an amazing world and story that will immerse you and take you for a great ride.

[Kady Ambrose · Rating 5 out of 5]

A wonderful blend of sci-fi/fantasy with an enemies-to-lovers central romance. Set on the relatively newly settled planet of Osivirius, the story’s worldbuilding is fabulous. The original colonists recreated Earth’s harshest practices with the elite in cold, shiny towers while exploited workers live and work underground in poverty and desperation. “Rebels” have left that world and created a nirvana by blending with the planet’s natural habitat and learning from the wisdom of the Masu, flying cat-like creatures who bond with human riders. Military helicopter pilot Jayden and rebel botanist Nettle are from opposite sides of this divide, each with inaccurate or incomplete understandings of the other’s worlds. They meet when Jayden’s helicopter crashes in rebel territory and Nettle and her brother discover him. I loved how Jayden and Nettle’s relationship evolved from antagonism and distrust to understanding and love over the course of the exciting drama. The low/no spice novel explores important issues in our life on Earth in an entertaining and engaging way, including environmentalism, inequality, materialism, and power. Highly recommend for fans of sci-fi, fantasy, and romance.

Thanks to the publisher for complimentary ARC. These opinions are my own.

[Jaxon Charlton · Rating 5 out of 5]

Really cool world. I like the sci-fantasy a lot. Interesting dynamics, though there are some story moments I would have liked to spend more time on. There’s a lottt of romance in this book. It’s very romance driven.

Enjoyable read! Very alike to James Cameron’s Avatar. Not very long but still fun

[Gabrielle Davis · Rating 5 out of 5]

Adventurous and imaginative, a tale of complex allegiances and the decisions we make when our values are put to the test. Highly recommend for readers who love Avatar and cats

[Rachel · Rating 5 out of 5]

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.

[Deanna · Rating 5 out of 5]

Great Sci Fi read for tween/teen readers. It was fast paced and fun.

[Book Reviewer · Rating 5 out of 5]

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.

[Next Best Read · Rating 5 out of 5]

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.

[Kailey · Rating 5 out of 5]

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!


I received a complimentary copy from the publisher. I was not required to write a positive review. All opinions expressed are mine alone.

[Birgit Lehmann · Rating 5 out of 5]

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.

[Siobhan · Rating 5 out of 5]

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.