Undertone: A Spicy Black Sci Fi Horror

by M.Q. Rush

“It isn’t sound. It’s him. And he’s choosing.”

They sent me to study strange frequencies in an alien ocean.

I didn’t expect the ocean to study me back.

There’s a creature here, and he isn’t made of flesh.

Not yet, anyway.

The more I record him, the deeper he gets inside me. The more I try to resist, the more he learns what makes me yield.

And when he finally shows himself, it isn’t for science.

It’s to claim me.

Author’s This erotic standalone is an intense, smutty read that includes rough sexual scenes. If such material offends you, please don’t buy this book.

58 pages, Kindle Edition

Published June 27, 2025

Reviews

[Angela Plumeria · Rating 5 out of 5]

Excellent unique little spicy novella. Well written and satisfying.

[Andi Downs · Rating 5 out of 5]

Another great read in this series. A short one but dark and gritty, following from the others but unique in it's own way. These have been enjoyable to read around other more lengthy books. Looking forward to the next one. :D
I received a free copy of this book via Booksprout and am voluntarily leaving a review.

[Nina Diab · Rating 5 out of 5]

'I need to document this. Need to analyze. But more than anything, I need to feel it again.'

Some books in this series I liked and others I did not. But I loved this one and it was by far my favorite. The storyline was unique and interesting from the start. Dionne is researching alone but I found her growing awareness of an invisible intelligent entity captivating. First a sensation, than pressure, a ghostly touch. Coming to her in ways she doesn't expect and her mind of a researcher is determined to learn more- and experience more. 5 stars

[Kaitlyn Kirby Kirby · Rating 5 out of 5]

Wow. When I started this one I wasn’t sure I’d like it but it was SO DIFFERENT and yet SO HOT! 🥵

Dr. Dionne Ellis, xeno-acoustics specialist is sent to look into vibrations after a whole team had a failed mission at an ocean planet base. What she comes to discover is a vibrations based entity 👀

I really loved how it played out with almost old school horror movie vibes, making you wonder what was even real.. until things get REAL lol

🌶️🌶️🌶️🌶️🌶️ most unique alien erotica ive stumbled across yet.. and I read a concerning amount of alien smut 😬😂

[Becky · Rating 5 out of 5]

First, I have never read a book like this one. That’s not a bad thing. Dionne is a scientist sent to a remote planet to continue research that had stopped under mysterious circumstances. Be prepared for some intense spice! I was completely absorbed in this story and the mystery woven into the plot. This is a fantastic short read!

I received a free copy of this book via Booksprout and am voluntarily leaving a review.

[Jorja Harrison · Rating 5 out of 5]

frequency

This dark suspense makes me wish I had paid a bit more attention in HS physics class. It it not really horror or particularly scary. It is very well written. Dub/con

Jorja Harrison (independent author)

[Barbara · Rating 4 out of 5]

Part of the Dark Tides, scientist Dionne is sent to study strange frequencies in an alien ocean. What she finds is that the sounds have a life of their own. I enjoyed reading. I received a copy of this book via Booksprout and am voluntarily leaving a review.

[Fritz Sands · Rating 4 out of 5]

I am not sure I would call this "alien romance" because the alien is not really romantic -- just all-consuming and possessive.

Anyways, hot erotica, reasonable horror, and an alien who manifests as sound. Quite enjoyable.

[Jen D · Rating 4 out of 5]

I can honestly say I've never read anything like this. I'm not even sure how to describe it. Very unique with great spice!.

I received a free copy of this book via Booksprout and am voluntarily leaving a review.

[Thatgirlthere · Rating 4 out of 5]

She's a scientist and he is... Sound. Very interesting read 🤭