This Poison Heart Review: Is It Worth Reading?

Verdict: A lush, smart Medea-meets-Secret-Garden YA fantasy with the best fictional moms in the genre, let down by a slow first half, a thin romance and a hard cliffhanger.

Best for: Readers who want mythology, plant magic and a warm Black queer family at the center of a gothic mystery, and who are fine with the sapphic romance staying a side plot until the sequel.

Heat level: ★☆☆☆☆ (1/5: young adult, closed door, a crush at most)

Rating: ★★★★☆ (3.8/5: a 4.09 Goodreads average across roughly 32,000 ratings, pulled down by the slow start nearly every critical reader names)

Tropes: Greek myth retelling, mysterious inheritance, plant magic, poison garden, secret family history, small-town secrets, queer parents, instant crush, chosen heir, duology opener.

This Poison Heart by Kalynn Bayron is the first book of a two-book sapphic YA fantasy series from Bloomsbury YA, a modern retelling of the Medea myth set in upstate New York, where a Black teenager who can make plants bloom with a touch inherits a crumbling estate, a walled garden full of things that kill, and a mysterious girl named Marie who seems to know far more about Briseis’s birth family than Briseis does.

It sits at a 4.09 average across roughly 32,000 Goodreads ratings, the highest-rated novel in Bayron’s catalogue, and it collected starred reviews from Publishers Weekly and Booklist plus a run of award shortlists. The reader reviews tell a slightly different story than the trade ones, though, and the gap between them is where the useful information lives.

What Is This Poison Heart About?

This Poison Heart is contemporary fantasy with a myth underneath it. The setting is real and present day (Rhinebeck, in the Hudson Valley), and the magic is botanical: tinctures, an old apothecary, a garden of deadly plants that only one bloodline can walk into safely. The Greek mythology arrives gradually, which matters, because the book reads like a cozy gothic mystery for a long stretch before it turns into something with gods in it.

Briseis has spent her life hiding what she can do. Plants respond to her, and poisonous ones don’t hurt her, which is a strange thing to carry when you don’t know where it came from. She was adopted, and her two mothers love her loudly and well, but neither of them can tell her why her gift exists. Marie, a wealthy girl who drifts into her life about a third of the way in, acts like she has the answers. The book is told in Briseis’s first-person voice, so you only learn what she learns, when she learns it.

What Makes This Sapphic YA Fantasy Work

The moms: Briseis’s two mothers come up in almost every positive review I read, and in plenty of the negative ones too. Readers keep calling them funny, present and the emotional heart of the book.
The poison garden: The walled garden and the apothecary are the most-praised piece of worldbuilding. Comparisons to The Secret Garden and, more than once, Little Shop of Horrors keep showing up.
The Medea twist: Readers who love myth retellings single out how Bayron reframes Medea. Locus called it a clever twist on the myth, and around ten of the Goodreads reviewers I tallied name the mythology as their favorite part.
Representation: A Black queer lead, Black queer parents and a cast of Black characters in a mostly white small town. Reviewers name this specifically and warmly, and Kirkus led with it.
Briseis herself: Readers find her funny and sensible. Several note she actually holds people accountable for keeping secrets from her, which is rarer in YA than it should be.

Book Synopsis

Briseis can coax a seed into full bloom by touching it. In the city that’s a party trick she can’t show anyone, and a burden she keeps carefully hidden, especially around plants that should make her sick and somehow never do. Then a letter arrives. An aunt she never knew, from the birth family she knows nothing about, has died and left her an estate in rural New York.

Briseis and her mothers drive up for the summer, expecting a fixer-upper. What they find is a house that has been waiting for her, with instructions left behind, a shuttered apothecary on the grounds, and a locked garden that holds some of the most dangerous plants in the world. Only someone of her blood can survive walking among them. Locals start showing up at the door, asking for remedies her family used to make, and Briseis starts to understand that her gift was never a random accident.

Then there’s Marie. She’s beautiful, guarded, and seems to know the history of the estate better than anyone living. Briseis is drawn to her at once, though Marie keeps answering questions with more questions. Meanwhile someone else in town knows exactly what grows behind that garden wall, and they’ve been waiting a long time for an heir to open it. As Briseis digs into who her birth family were and what they protected, the question becomes how much of her inheritance she can afford to learn, and who she can trust while she learns it.

My Review

The family is the best thing here, and I’d put it up against anything in YA fantasy. Briseis’s mothers aren’t the usual absent or dead YA parents. They’re in the car, in the kitchen, in the garden, cracking jokes and worrying out loud, and the warmth between the three of them gives the darker material real weight. When the book puts that family in danger, it lands, because Bayron spent the time making you care.

The second strength is atmosphere. The estate, the overgrown grounds and the garden of deadly flowers are written with obvious love, and the plant magic feels tactile in a way most YA magic systems don’t. Publishers Weekly praised the gothic mood and the way science and myth blend into the lore. I agree with that, and so do most readers. When the Medea material finally surfaces, it reframes what you’ve already read in a satisfying way.

Where it struggles is pace, and this is the complaint I saw most often by a distance. Of the thirty or so reader reviews I read closely on Goodreads, around eleven say the first half is slow, meandering or repetitive, and a few add that the opening leans on info-dumping. The pattern is consistent: people describe a long, quiet setup and then a final act that moves so fast it feels rushed. Five reviewers call the ending messy, abrupt or crammed, and one blog reviewer says she felt sold one book and handed another.

The romance is the other soft spot, and readers should know going in that it’s secondary. Marie turns up about a third of the way through and Briseis has an instant crush. Seven of the reviews I tallied call the romance forced, rushed or underdeveloped. Without spoiling it, a reveal about Marie also raises an age question that several readers found uncomfortable, and StoryGraph’s community warnings list it. One blog reviewer read Marie’s secrecy as red flags rather than romance. The Lesbrary’s reviewer felt real chemistry, so this one splits.

Last thing to calibrate: this isn’t a standalone. Book one ends on a hard cliffhanger with a loss that the sequel picks up from immediately. The good news is that the duology is finished, so you can go straight on.

My honest note: A four-and-a-half-star family and setting wrapped around a three-star structure. If you want the sapphic romance to drive the plot, this will frustrate you. If you want myth, mystery and a family you’d move in with, stick out the first half and keep book two nearby.

Element	In This Poison Heart
Central relationship	Briseis and Marie: a new girl in town and a secretive local, an instant crush that stays a side plot in book one
Core tropes	Greek myth retelling, mysterious inheritance, plant magic, poison garden, small-town secrets, queer parents
Setting	A crumbling family estate with a walled poison garden near Rhinebeck, New York, present day
Heat level	1/5: young adult, closed door, no romance.io band
Series	This Poison Heart duology book 1. Ends on a hard cliffhanger. Book 2, This Wicked Fate (2022), completes the story
Content notes	Death of a parent, murder, violence, blood and injury detail, grief, some body horror and gore, kidnapping, racism, an adult/minor relationship concern

How Spicy Is This Poison Heart?

A 1/5. romance.io has no entry for This Poison Heart, which is the norm for young adult titles and tells you it isn’t being catalogued as romance at all. Publishers Weekly lists it for ages 13 and up and Kirkus for 14 to 18. Reader reviews back that up: the attraction between Briseis and Marie is mostly glances, closeness and unanswered questions, and several readers say the romance barely gets going in book one.

The thing worth knowing in advance is the age question around Marie. StoryGraph’s crowd-sourced warnings include an adult/minor relationship tag, and multiple reviewers raise it, so if that’s a dealbreaker, read the spoiler warnings before you start. Nothing on the page is sexual. If you want other YA sapphic fantasy at the same low heat, The Scapegracers, Sweet & Bitter Magic and The Coldest Touch sit in the same band.

Who Should Read This Book?

You’ll likely love it if: you love Greek myth retellings with a fresh angle, you want a loving queer family front and center, you enjoy slow-building gothic mysteries with plants and old houses, and you’re happy for romance to be a subplot.

You may want to skip it if: you want the sapphic romance to be the main event, a slow first half makes you put books down, cliffhangers make you furious, or an age gap in a YA romance is a hard no for you.

In short: Come for the moms and the poison garden, stay for the Medea twist, and don’t come for the love story yet.

What Readers Are Actually Saying (October 2026)

This is a five-year-old book with steady, institutional discovery behind it rather than a viral moment. The accolades are the story: Publishers Weekly and Booklist both starred it, Kirkus, Locus and the Bulletin of the Center for Children’s Books reviewed it positively, and the author’s site lists an Indie Next pick, a Booklist Editors’ Choice, a Junior Library Guild Gold Standard selection, the Rainbow Book List, and Locus and Ignyte finalist spots. That’s library and school shelf placement, and it explains how it climbed past 32,000 Goodreads ratings and almost 6,000 written reviews. UK editions are sold as coming “from the author of the TikTok sensation Cinderella Is Dead,” which tells you the BookTok energy belongs to Bayron’s debut, not this book. I didn’t find a meaningful Reddit footprint through search.

The audiobook is narrated by Jordan Cobb and runs 10 hours and 17 minutes, released by Bloomsbury the same day as the hardcover in June 2021. One audiobook blogger gave it five stars and praised the pacing, which is a minority view, so if the slow start worries you on the page, audio may be the easier route through it. I didn’t find listener comments about Cobb’s performance specifically.

Prefer audio? Listen to This Poison Heart on Libro.fm, the audiobook shop that supports independent bookstores.

Why readers love it (according to the discourse): The mothers come first, and about ten of the reviews I tallied name them. The mythology and the Medea angle come up just as often. The plant magic and atmosphere follow, with “Secret Garden” as the recurring comparison. Representation is the fourth constant. A notable minority also praises the pacing outright, including the audiobook blogger and Kirkus, which called it well paced.

What readers argue about and complain about: Pace, above everything. Around eleven of the thirty reviews I read closely say the first half drags, and the complaint is about structure: a long setup with too much repetition, then a final act that crams in the reveals. Second, the romance. Seven reviewers call it forced, rushed or thin, and a reveal about Marie’s age bothers several of them. Third, the ending, which five readers describe as rushed or messy. Smaller threads: four readers find Briseis slow to connect obvious clues, three call the slang or representation heavy-handed, and two find the villain weak. Readers split on the midpoint shift into Greek myth: some think that’s where the book comes alive, others feel it abandons the garden mystery they signed up for. None of the trade reviews I found mention the slow start or the age question, which is the gap worth knowing about.

The series question everyone should ask first: Book one ends on a cliffhanger built around a death in Briseis’s family and a deal with a deadline. The sequel, This Wicked Fate (2022), picks up directly from there and completes the duology. It rates a little lower at 3.97 across about 15,500 Goodreads ratings, and the Lesbrary called it a satisfying ending, though one reviewer found it less fun than book one. The good news for the cliffhanger-averse is that both books are out, so read them back to back.

Frequently Asked Questions

Does This Poison Heart end on a cliffhanger?

Yes, a hard one. Book one ends with a loss in Briseis’s family and a deadline that the sequel, This Wicked Fate, picks up immediately. Both books are published, so you can read straight through.

Is This Poison Heart a romance?

Not really. It’s a young adult fantasy and mystery with a sapphic romance subplot. Briseis’s crush on Marie develops more in the sequel, and several readers say the romance feels rushed or thin in book one.

How spicy is This Poison Heart?

A 1/5. It’s young adult and closed door, with nothing sexual on the page. Publishers Weekly lists it for ages 13 and up, and romance.io has no steam rating for it.

Is the This Poison Heart series complete?

Yes. It’s a duology, and This Wicked Fate (2022) concludes it. The sequel holds a 3.97 Goodreads average, a little below book one’s 4.09.

Is there an audiobook of This Poison Heart?

Yes. Jordan Cobb narrates the unabridged audiobook from Bloomsbury, which runs 10 hours and 17 minutes. It’s available on Libro.fm and Audible.

Is This Poison Heart a Greek mythology retelling?

Yes. It’s a modern retelling of the Medea myth, mixed with a Secret Garden style poison-garden mystery. The mythology surfaces gradually and takes over in the second half.

If You Loved This Poison Heart, Read These Next

Stay with Kalynn Bayron for Cinderella Is Dead, her fairy tale retelling with the romance far more central, though readers rate it lower. For witchy found-family magic in a contemporary setting, try The Scapegracers. For a curse, a heroine hiding a dangerous gift and a romance that gets more room, go to Sweet & Bitter Magic. And if you want a YA sapphic fantasy where the world goes bigger, Girls of Paper and Fire is the obvious next step. There’s more on our YA sapphic fantasy books list and across our book reviews.

The Bottom Line

This Poison Heart wants to be a myth retelling, a gothic mystery and a family story all at once, and it mostly pulls it off. The mothers are wonderful, the poison garden is a gorgeous setting, and the Medea twist earns its starred reviews. The first half is slow, the romance is thin and complicated by an age reveal, and the ending rushes into a cliffhanger. If you love mythology and want a queer Black family at the center of a fantasy, it’s worth your time, especially with the sequel ready to go. Check This Poison Heart on Amazon →

The Eikna Overall Ranking

On the Eikna scale, This Poison Heart ranks as an award-shortlisted YA myth retelling with a sapphic subplot. It’s warm and atmospheric, held back by a slow first half and a thin romance, and best read for the family and the Medea twist rather than the love story.