Plastic: A Coming of Age, Young Adult, Ocean-Based Horror Thriller

by Marisa Noelle

The ocean took her brother. Now, something far worse is rising from the deep.For three years, Sara Monroe has blamed one thing for Danny’s EnRG—the billion-dollar energy drink empire flooding the ocean with its toxic plastic waste. A single piece of the corporation’s toxic trash trapped him beneath the waves, and she’s spent every moment since fighting to make sure it never happens again.

But something is wrong with the water. The sky is turning green. The waves pulse with an unnatural glow. And when EnRG announces a revolutionary plan to "clean up" the ocean, Sara knows they’re hiding something—something dangerous.

Then the bodies start washing up.

Something is lurking in the deep, feeding off the very pollution Sara has sworn to fight. It moves unseen beneath the waves, growing stronger, waiting. And when it rises, no one will be safe.

The ocean has a new apex predator. And it’s hungry.Reviews for Plastic ★★★★★⭐⭐⭐⭐⭐ “A gripping eco-thriller that will haunt you long after the last page.”
⭐⭐⭐⭐⭐ “An electrifying mix of suspense, horror, and heart—this book is impossible to put down.”
⭐⭐⭐⭐⭐ “Part JAWS, part Erin Brockovich—Sara Monroe is a heroine you won’t forget.”
⭐⭐⭐⭐⭐ “Dark, thrilling, and terrifyingly relevant. This story will pull you under.”
⭐⭐⭐⭐⭐ “A must-read for fans of environmental thrillers and pulse-pounding horror.”

308 pages, Kindle Edition

Published November 4, 2025

About the author

Marisa Noelle is the author behind a treasure trove of young adult and adult novels across multiple genres, but they all have running themes of mental health or the ocean. She tends to gravitate towards the speculative arena and loves to write science-fiction, fantasy, horror, dystopian, romance, romantasy, or a combination of them all.

Marisa's books include:
The Shadow Keepers—a spine-tingling tale to keep you up all night and semi-finalist of the BBNYA book awards.
The Unraveling of Luna Forester—a novel impossible to talk about because of its huge twist, but it snagged several awards, including: First Place Incipere Award, WriteBlend Finalist, BBYNA Semi-Finalist, Bookshelf Finalist shelf.
The Unadjusteds Trilogy delves into one of her favourite genres—dystopian. The Unadjusteds, the Rise of the Altereds, and The Reckoning make up the trilogy, but there are eleven further companion novellas that follow the secondary characters. The Unadjusteds also placed as a semi-finalist in the BBNYA awards. There are also eleven origin story novellas set in The Unadjusteds universe that are completely FREE when you subscribe to my website.
The Mermaid Chronicles is a seven book romantasy series that includes: Secrets of the Deep, Quest for Atlantis, Fight for Freedom, Ghost Pirates, Vendetta, Denizens of Darkness, Vorago Returns, as well as its own companion guide. The entire series is coming to audio with Tantor Media soon!

Marisa also writes steamy romance under the pen name Savannah Warner.

When Marisa's not weaving literary spells, she's helping mold the future of MG and YA authors as a mentor for the Write Mentor program.

When not writing, Marisa likes to imagine herself as a mermaid, and can often be found in the local pool…or lake…or ocean. Despite her undeniable bookworm credentials since she was knee-high to a grasshopper, the author gig took Marisa by surprise. You see, she had a secret past as a bit of a science geek during her school days. But hey, science and storytelling make a surprisingly magical concoction! Currently, Marisa calls Woking, UK, her home sweet home, where she resides with her trusty squad, including her husband, three amazing kids, and a furry four-legged friend named Copper.

Reviews

[Siobhan · Rating 2 out of 5]

I recieved an ARC of this book in exchange for an honest review.

Plastic is an eco-friendly thriller, following Sara as she tries to clean up her local beach, even as the levels of trash pile up, attract an unusual algae, and grow into something almost sentient. Can one eco warrior save the world?

I really wanted to like this book, it had such an interesting premise. I liked the idea that while we worry about technology gaining sentience, our rubbish could potentially do it too. And certainly Marisa has a way with words, her characters were fleshed out and she had a message she wanted to convey. A lot of her prose was reminiscent of Stephen King for me.

But unfortunately, I have never enjoyed Stephen King. While he builds horror, he is inconsistent with timings and sometimes he's so overblown in his descriptions that my sense of disbelieve can no longer be suspended, and that was often my problem with the narrative in this book. The trash monster developed too quickly, though there were efforts in the prose to explain it away. The monster became so big and unstoppable that the horror I was waiting to feel was replaced with a mild wondering about how everything was going to come good in the end, whether it was going to be a deux ex machina at the end. The bad guy, Regina, was such a caricature that I suspected she wasn't the bad guy. There was so much mention about Sara's brother Danny, who died before the narrative, that I began to wonder if his sentience was tied to the monster (it wasn't, I feel like that could have been an interesting twist) in short, I spent a lot of time reading this book overanalysing it, and not immersing properly in the narrative.

I made a fair few notes as I was reading, things that feel like plotholes or underdeveloped ideas. Like, Tyler - Sara's boyfriend - often went flying in planes, but he didn't believe Sara that the trash island existed until it came in land, when a plane offered a perfect vantage point. The correlation between EnRG, the company behind a lot of the trash and Danny's death, and the algae was established early, and Sara even recommended nurses use the drink to heal those hurt by the algae, but it was an eleventh hour epiphany of hers to use EnRG to save the area from the growing threat, which was very infuriating for me.

I also felt like some of the prose was misplaced. For example, Tyler's father gets chemical burns from the algae, but Sara is waxing lyrical about the photos on display (this occurs in her house) when she knows how to treat the father, so the tension of the algae coming into the house through the water system is completely diluted by her reminiscing. Likewise, there are some tense scenes where Sara randomly mentions her family's swear jar. Who cares about the family swear jar when you cuss in front of a friend when you're dealing with mortal peril? It felt so irrelevant. Screw the swear jar. I hated the swear jar. The swear jar alone stole a star off my rating.

The other issue I have with King, that I had with this book, is the understanding of timings. For example, I have a note that says on page 163, the neighbour was having a shower in the morning, Sara and her friend have just had breakfast when they rescue her from her shower burns, they have a talk with the paramedics ... and then it's twilight. There's no modifier for the passing of time, and this is happening in California in summer, a place that doesn't experience twilight days like in the Arctic circle. Overall, it lent to Sara being an unreliable narrator, and there were other inconsistencies that had me feeling that way, so that when Sara was so sure of her theories, I couldn't get behind her or understand why the other characters were doing so.

I'm glad that the monster's ending was consistent with some of the set up of the book, Tyler flying planes that could spread water, but using EnRG to defeat the trash monster was a nice conclusion, but it was an agonising wait for that conclusion, like when it took all of Eclipse for Bella and the Cullens to realise they were dealing with Victoria and the Newborns despite the early establishment.

As I said, I wanted to like the book. Marisa writes well and the concept is an intriguing one, but this story just felt so unpolished. I would have loved for Danny to have been part of the monster, and Sara being instrumental in appealing to his soul to let go while Tyler released the EnRG, so that there was more stakes in resisting getting rid of it for so long when they had the solutions in their hands the whole time. And to yeet the swear jar to the bottom of the ocean, but that one is definitely personal preference.

[Meghan · Rating 3 out of 5]

Thank you to Marisa Noelle and team for allowing me to be an ARC reviewer for Plastic! I'm grateful for the opportunity to read this ARC and leave an honest review.

I had a lot of mixed feelings about this book as I read. Based on my knowledge of the author and her previous works, her plot really focuses on environmental awareness and the ocean, even in fantasy settings. The primary protagonist, Sara, is the embodiment of these values - she champions caring for the ocean, recycling when she can and finding alternatives when she can't, pushing her family and friends to use eco-friendly products. It can become easily overbearing as it feels like every other line has to include something about Sara pro-environment lifestyle. And maybe it's because I'm no longer part of the targeted age demographic, but these teenagers felt very annoying at times. The solution to fighting the Great Green was in front of them the entire time, but it's not until the end that Sara has the epiphany to finish the monster. I had higher hopes for the plot, but I still enjoyed the read.

[Mickey · Rating 4 out of 5]

*ARC REVIEW*
What happens when all the trash that finds its way into our oceans, turns into something worse? Sixteen year old Sara is one of the first to notice what's happening just off the shore, but no one believes her. She and her friends set out to kill the monster and save their ocean.

This story really hit home for me—it shows just how dangerous and devastating ocean trash can be. So many people just ignore the problem, even though it kills sea creatures every single day. What I really liked was how it pointed out that people usually only start paying attention once it affects them—like here, when the trash literally turns into a giant monster.

Overall, it was such a unique, eye-opening story, and I honestly really enjoyed it.

[Marisa Blagden · Rating 5 out of 5]

⭐️⭐️⭐️⭐️⭐️ — A gripping, timely, and unforgettable eco-horror that sinks its claws in and never lets go.

Plastic is a razor-sharp, ocean-soaked thriller that blends YA coming-of-age emotion with pulse-pounding horror—and the result is utterly magnetic. From the first chapter, Sara Monroe’s grief is palpable, her determination fierce, and her rage at EnRG’s environmental destruction both powerful and heartbreakingly real. This is a heroine you root for instantly.

What makes Plastic stand out is how seamlessly it marries character-driven storytelling with environmental dread. The water shifting colors. The sky turning sickly green. The waves pulsing with an unnatural glow. Every eerie detail builds a creeping sense of doom—until the horror beneath the surface finally erupts.

And when it does? Chills. Absolute chills.

The monster that rises from the deep is more than a creature—it’s a consequence. A terrifying embodiment of pollution, corporate greed, and negligence, and its presence transforms the story from a mystery into a full-blown, heart-stopping nightmare. The suspense escalates with every chapter, and the scenes at sea are so vivid you can almost taste the salt and fear.

Highlights:
🌊 A fierce, emotionally grounded heroine whose grief fuels every decision
🧪 A horrifyingly believable eco-monster born from plastic pollution
⚡ A relentless pace with twists that keep you breathless
🌱 A powerful environmental message woven naturally into the narrative
💔 Found family dynamics that deepen the emotional stakes
🔥 Action sequences worthy of a blockbuster thriller

Part JAWS, part Erin Brockovich, and part something entirely new, Plastic is a standout YA horror that feels both wildly imaginative and terrifyingly real. It’s the kind of story that crawls under your skin and lingers long after the final page.

Tense, emotional, and frighteningly relevant. A five-star eco-horror triumph.

[Horror Reads · Rating 4 out of 5]

A giant green glowing sea monster made from the oceans trash, environmental activism, and a greedy energy drink company all combine in this novel of high octane horror.

Sara lost her brother to the ocean. He was trapped under plastic while diving and died when his oxygen ran out. This has haunted her for three years and she is a very outspoken and active environmental activist cleaning trash from the beach.

When an energy drink company vows to clean up the ocean in a seeming change of heart, Sara is suspicious. And it doesn't take long before the trash turns into something sentient and something which wants to take over the oceans and water supply. It will stop at nothing and causes death and severe injuries to anyone who attempts to venture into the water.

But the company covers it up and Sara, along with her best friend and boyfriend and a marine biologist won't allow this to happen. However, with an indestructible monster getting bigger and more vicious and being followed by men in dark suits threatening them, tension is high and the dangers get very real.

This is a good creepy YA novel and it talks about the oceans trash problem with an eye towards the horrific. The monster is binding with the waster, mutating, and growing at a fast rate. The grief over Sara's brother is her guiding force and her love of the ocean is evident throughout. Action sequences are exciting and unpredictable and that's always a good thing!

This features a creature unlike any you've ever read and I highly recommend it. I received an ARC of this book from the author. This review is voluntary and is my own personal opinion.

[Dan Mckeithan · Rating 4 out of 5]

Plastic is what happens when you cross a company set on polluting our waters with young adults trying to stop them. Marisa does a great job in this eco horror that is shows what this waste can potentially lead to in our environment. The creature feature part of the story and the way the young adult characters handle it shows great characterization. Awesome story that makes you think!

[Joseph Lau · Rating 5 out of 5]

Overall, a good story focused on the effects of rampant pollution and greedy operators who try to fix the problem.
Characters are primarily teens—interesting and fun with quirky personalities. A bit heavy on the anti-corporate / pro environmental rescue stuff (good points—just seeing the characters flipping out about climate destroyers gets redundant).

[Emma Read · Rating 5 out of 5]

A twisty, gripping, ocean eco-thriller perfect for fans of Jaws! The author's love of the waves comes across clearly, but so does the terror! But more than that, this is a story of grief and loss and overcoming, and fighting for truth and what's right and I loved this balance