A Terror Triptych: Ostara

by Kasey Fallon

Spring. Where everything blooms... and bleeds.


The third Terror Triptych: Ostara arrives Spring 2026 with three tales of seasonal dread; Rootbound, Marrowseed, and Osedax, where renewal rots from the inside out.

Blooms. Blossoms. Blood.

In Rootbound, a woman returns to a Nordic village and a waiting garden that refuses to be denied. In Marrowseed, a restorative retreat cultivates transformation at a terrible cost. Finally, in Osedax, beneath the rising Worm Moon, earth and ocean answer an ancient hunger.

This spring, what grows is ravenous. And the first thing it devours is you.

113 pages, Kindle Edition

Published March 20, 2026

Reviews

[Sarah · Rating 4 out of 5]

Fast-Paced and Eerie

A Terror Triptych: Ostara is a trio of short, spring-themed horror stories that are immersive and creepy. From too-lush gardens that come with costs to Scandinavian forests to Chesapeake wetlands, these were chilling and exciting at the same time. I enjoyed them, but would definitely not read these at night.

[Amanda Elizabeth Myers · Rating 4 out of 5]

3 short stories about nature and how it can be beautiful but deadly.

[Jordan · Rating 5 out of 5]

This book feels like spring… if spring had a sinister agenda.
Fallon takes something normally associated with warmth and renewal and flips it into something deeply unsettling. The writing is immersive without being overdone—there’s a steady, creeping tension that builds quietly and then lingers with you long after you put the book down. It’s not just “jump scare” horror—it’s the kind that makes you side-eye your garden, your surroundings, even your own thoughts.
What really stands out is the atmosphere. Each story feels intentional and cohesive, like pieces of a larger emotional puzzle, yet distinct enough to keep you hooked the entire way through. The themes of nature, decay, and transformation are handled in a way that feels both poetic and disturbing (in the best way).
If you like horror that is:
psychological rather than purely graphic
a little eerie, a little existential
and quietly haunting instead of loud
…this one absolutely delivers.
Final verdict: A beautifully unsettling read that proves not everything that blooms is meant to be trusted 🌱🖤

[Mary Urban · Rating 4 out of 5]

This trilogy could be named The Beauty of Terror. There are a lot of things to love about these books, but I’ll pick how the author can tell the most horrendous things so lyrically. The trilogy is a delicious slow-burn dread, exquisitely paced, where it’s hard to choose a story over the others. The books are also a sure reread, because there are a lot of precious details that can be missed in a first, hurried reading. I haven’t read anything from Kasey Fallon before, and it’s been a great discovery. She has become one of my favorite horror writers. It's a shame that the last story in the third book diverges so much from the rest, because it would have been another five-star read. There's a huge difference between terror, horror… and disgust.

Horror doesn't have to be ugly to be truly terrifying.

Four stars, because I'm still in love with the rest.

I received an advance review copy for free, and I am leaving this review voluntarily.

[Claire ellison · Rating 4 out of 5]

In this book, we look at three interconnected stories that asks the questions, what if spring's renewal came with a literal blood price. This book shines through the writing of Kasey Fallon, as she crafted the beautiful atmosphere that surrounds each story. It provides the slow sense of dread and cloaks the horrors that lurks beneath the surface. This is a must read for horror fans especially those who are looking for a folk horror. I am so excited to dig into more of her catalogue.

I received an advance review copy for free, and I am leaving this review voluntarily.

[Christina · Rating 3 out of 5]

This is a arc reveiw
Title -> A Terror Triptych Ostara
Author -> Kasey Fallon
Rating⭐️ -> 3.5/5
Genre 🎃 -> Horror/ Fantasy Paranormal thriller
Main Character 🎎 -> Mara
Main Trigger Warnings ⚠️ -> Suicide/ Violence/ Death
Pages -> 120
this was a arc I read

this book was filled action packed. it had so much going on. Mara goes back to her home town her grandmother died. Everyone seemed to know who Mara was and keep asking if she is going to plant into the circle? what is with this circle and these seeds??
They offer growth/ blood / seeds. monster root took a guy named bram and in return it offers the land to be fertile no plagues no drought. In the spring the earth wakes during this time you can watch prepare and respect it. there is something beneath the soil. There is bone eating worms osedax rowan finds a dead whale carcus and tries to take a picture of the worms to see if they are the ones that eat bones he falls threw the dead whale side and worms get all over him he rips his scuba suit of and worms begin to..... Alec and koda are on a boat they hear noise and then see white and red worms borrowed into the hull of the boat there was 10 men and 6 only made it to the life raft. they went to the house and the dog was covered in the worms they try to use salt and diatomaceous earth which is sharp dirt. Sierra goes down stairs and the shelf falls on her and there she lays on the ground covered in worms.

there was a lot going on. I was little lost but I liked them they were good. well written kept you interested. Just like different things happening and then you got invested into a story then it was onto something else

[Kristen N · Rating 4 out of 5]

A Terror Triptych series always has the most eerie and absolutely perfect horrors inside and this one was the cherry on top.

Each story has to deal with nature. While we know nature is beautiful, we are also aware that its dangerous in its own way. I love the way the author always seems to be able to twist the stories into something utterly mindblowing, leaving you gripping the edge of your seat.

[Shari · Rating 3 out of 5]

Three bite-sized horror stories, perfect for when you're craving a small scare. Devoured this book in 1 sitting. Story #3 especially gave me the creeps.😱 Scary but not so much that I couldn't sleep after. Satisfied my horror craving.

Thank you to the author, the publisher and Goodreads! I was thrilled to win this ebook in a Goodreads giveaway.

[Sarah Savard · Rating 4 out of 5]

Another good book in this series. There's 3 stories in each book & Ms. Fallon turns Spring into the season of nightmares in Ostara. I love horror (of all kinds) & this is freaky enough that makes me want to re-read again. I will be looking for more by Kasey Fallon.

I received an advance review copy for free, and I am leaving this review voluntarily.

[Stuart · Rating 5 out of 5]

This was a nice weekend read--short, yet exciting book. All three stories were good, but I would say that Marrowseed was my favorite. I look forward to reading more from Kasey Fallon!

[Megan · Rating 5 out of 5]

Really interesting writing style that gives you a different perspective of the spring season

[Eileen Cox · Rating 4 out of 5]

I received this book as part of a Goodreads giveaway.

Three short spring themed horror stories. Perfect for people who enjoy seasonal reads. Third story was my favorite.