Overgrowth is another sci-fi hit from Mira Grant. I'd definitely say this is for fans of science fiction with sprinkles of horror. I wouldn't say it's horror as much as an intense sci-fi thriller with horror elements.

As someone who loved Into the Drowning Deep, Overgrowth was easily one of my most anticipated releases for the year. I love science fiction and horror and so I am always on the hunt for books that successfully mash these genres together.

Unfortunately this one did not work well for me. The entire premise and plot felt unbelievable, breaking my suspension of disbelief.

This one just felt silly. I also struggled with the age classification. This is technically classified as adult horror but everything about the characters and plot fit perfectly within the tropes of YA horror. I would have preferred a more mature version of this story.

I did appreciate the author using the aliens as a way to discuss human issues. However, despite agreeing with the author's point, I found this heavy handed.

I would recommend this one as I don't feel it's representative of this author's talent. I wanted this one to be a new favourite and was disappointed when it didn't work.

Disclaimer I received a copy of this book from the publisher.

This book honestly feels more YA than adult, and I think this is largely due to the characters. I believe they're all supposed to be in their late twenties or thirties, but read more like they were teenagers. The genres also contributed to the YA feel. It's primary genre on Goodreads is horror followed by sci-fi, but this isn't accurate. It's much more of a cozy sci-fi with a very light horror element.

The pacing of this one is really slow. The first two-thirds of the book is essentially set up and the characters finding themselves in somewhat repetitive situations and a lot of conversations. Things then pick up pretty quickly towards the end, but it was a slog to get there. Unfortunately, I didn't find the characters to be strong enough to support the slow plot. They're relatively static, with several of them feeling very tropey (the perfect boyfriend being one of them).

While this book has an interesting premise/concept, it just didn't work for me. If you like cozy sci-fi with a YA feel that moves slowly, you may enjoy this. My thanks to NetGalley and Macmillan Audio for allowing me to read this work. All thoughts and opinions expressed in this review are my own.

The Day of the Triffids, turned up to 11.

It's not what I expected in an apocalyptic story. It’s almost entirely focused on Stasia as a character and her immediate circumstances. There is almost none of the overarching societal collapse that you usually get in apocalyptic stories. It was more of a character study, focusing more on Stasia’s state of mind, how she relates to the humans around her and how that starts to shift as the invasion unfolds. It explores themes of prejudice, identity, belonging, and the ethics and failure of our institutions. I really admire how well Stasia’s changing attitude was done and how it matched her physical metamorphosis, as well. I was with her every step of the way.

The standout side characters are absolutely Graham and Toni. The relationship between Graham and Stasia was really beautiful. The story never felt like it was going to go in humanity's favor and the most distressing part of that was definitely how or if Graham was going to survive… because he HAD to survive, right? …RIGHT? Toni was a fascinating character on her own, but I really didn’t understand her motivation for staying with them. I know what she claimed (repeatedly) but her actions didn’t match up. The aliens were mostly interchangeable to me, but I did really like Hunter!

It’s not a 5 star read for me because of the pacing. There were a couple of places in the middle where the explanations were getting a bit tedious. A lot of the book is about what the invaders are and what their methods are and how the invasion should go. I can certainly see how it could be gold for those readers who live on great worldbuilding, but I was ready to get back to the story after a while.

A young girl discovers a beautiful flower in the woods, and the incursion begins.

It feels wrong to give this book a 3, because it was a blast to read. I found myself absolutely engulfed by the story, especially within the first half. Unfortunately, the book is weighed down by an anticlimactic ending (or an overall tame story) and a lot of questionable moral statements.

The book looks at identity, otherness, and the nature of humanity. The story is about an alien species looking to spreed its seed. At the start, it reads almost like a warped wayward children story of a seedling looking for a world where they belong and are accepted. Anastasia is an alien. She tells everyone that from the start. Of course, no one believes her, but nevertheless she finds her group who accepts her.

One of the central themes in Overgrowth is the idea of accepting people as they present themselves, even when they seem strange or unbelievable. This feels like its intended to mirror the language of queer and trans allegory, and on the surface, the story seems to celebrate radical acceptance. However, I think the metaphor starts to unravel under scrutiny.

The story equates claiming to be an alien with claiming a gender identity, but that parallel feels ethically and conceptually shaky. Gender is a social construct that is fluid and culturally embedded, while species identity is a material and biological distinction. Framing gender queerness as analogous to identifying as an alien risks trivializing it, reducing it to a quirky or harmless fantasy rather than a lived reality grounded in both experience and social struggle.

More troublingly, this metaphor sidesteps the dangers of uncritical acceptance. We live in a time shaped by science denial and conspiracy theories. The idea that all claims should be accepted at face value, even fantastical or self-serving ones, can be harmful. Some beliefs and identities, especially when rooted in harmful ideologies, deserve interrogation, not affirmation. The book’s message of blanket acceptance might work as allegory, but it brushes aside the need for discernment in the real world.

I can't say this a critical failure of the book, but it is framed as a fundamental aspect of the narrative. The entire invasion is justified by the lack of acceptance of these claims of being alien in the most cringe way. The entire invasion could have been avoided the humans had just accepted what they were told as truth and told the messengers that they did not want to be invaded. As a mechanic, I don't think it fails completely, but it becomes a literal justification by our main character for why humans deserve whats coming.

It is our failure to believe people are who they say they are, even when there is absolutely no reason to believe such an extreme claim. It intersects with my original concern around the harm of critical thinking and asking what is and isn't worth believing. Imagine if the moral of this story was taken literally. What does it even mean to believe? One character is said to have decided to believe what they were told, as if belief is something we can just decide to have or not have.

I almost forgot another thing that really frustrated me: using NASA as the representative of the big bad government. Realistically, this is my smallest critique as its more personal, but I think it is a huge mischaracterization of NASA to lump it (and the astrobiologists within it) into the militant part of the government. They literally worry about a robot on Mars might disturb possible microbes. As a astrobiologist and planetary scientist, I assure you, NASA scientists would almost certainly advocate peace.

At the end of the day, I enjoyed this book, but I feel uncomfortable with some of its messaging. I also think it needed more horror and less exposition. At the very least, it was thought provoking which made for an engaging read, and for that I am grateful.

I was hooked from the beginning!
It was amazing and engaging.
I was instantly sucked in by the atmosphere and writing style.
The characters were all very well developed .
The writing is exceptional and I was hooked after the first sentence.

3.5 stars

I'll be curious to see the reviews of this book. The book had some pacing issues, and there were parts that I LOVED and parts that dragged a bit. I really appreciated the commentary that is in this book, and the discussion around immigration and human rights.

4.9 stars
Thank you to Netgalley and Macmillan Audio for an advanced copy of this

Mira Grant wrote of my favorite horror books that I reread every single Summer, Into The Drowning Deep which is a fantastic dark mermaid tale. It is very hard to find dark mermaids. She did it again with aliens this time. One afternoon toddler Stasia goes into the dark woods and when she returns she insists on telling everyone that crosses her path that she is an alien in human form. She tells them that someday they will come for her and one day they do. Lets just say that this is not a great family reunion.

Unfortunately, I kind of hated this book. I did think about giving it three stars because the first half or so was pretty good, but the back half is one of the most frustrating books that I've read in a while, so I just couldn't. I was really looking forward to it, too. I remember the press release that Nightfire put out about publishing the next two Mira Grant books and how much of a big deal that was, plus the description and synopsis sounded amazing. And yes, the beginning was great. It hits the ground running with a pretty gruesome child murder and super creepy Invasion of the Body Snatchers introduction to the main character, but then the first problem hits with the most insane tonal whiplash I think I've ever read because it turns into a cute YA book out of nowhere. And yes, even though the characters are all stated to be in their 30s, not a single one of them acts a day over 22 at any point in the book, so it's for sure YA. Still, I was pretty on board because it was still fun until the actual invasion when it became unbearable. I'm not going to go into too much detail because I had the exact same problems as quite a few other people, but Anastasia is just objectively the villain of the story no matter how much Grant seems to want us to empathize and side with her. Her horrendous plant vampire species come to essentially torture the entire planet to death by slowly and painfully draining their blood until they die, very much including all children, and neither she nor anyone of them even feel any real guilt about that. I think if the story was told with her just being either obviously evil or realizing that her invasion is super evil and trying to turn things around, the story might have worked better, but she's constantly in this middle handwringing stage that's just so annoying and preachy to listen to. The book is easily 200 pages too long, so you're going to sit through A LOT of that preaching and trying to justify child torture, too. Then, there's the whole wonky political messaging thing that people have mentioned several times and the fact that most of the actual action takes place offscreen, but one of the other problems that I had with it is just how stupid the logic of the whole thing is with a bunch of plants conquering the planet so easily. They're all literal plant monsters, so why did no one seem to think of just lighting their ships on fire? There's some talk about weed killer being used, but that just seems unnecessary? A few of the plant people do get killed by being shot and all of their ships seem to be a bunch of flying roots, so it seems like fire would be a pretty good defense against a bunch of sentient plant monsters. I don't know, it's just a thought. Lastly, this is absolutely not horror. Especially not body horror, unless you think your skin peeling after a sunburn is body horror, because that's about the extent of what happens to the plant people when they change green. Man, I really wanted to like this one. I'll still try to check out the other one that she's putting out with Nightfire, but this was massive miss for me, even though the narrator for the audiobook was amazing.

Rounding up to 4 stars because in the end I like a lot more about it than the things that didn't work as well for me.

Overgrowth is a found family adventure story set on the eve - and during the event of - an alien invasion, one that's been warned for about thirty-some-odd years. It's Invasion of the Body Snatchers, but very queer and told from the first person point of view of one of the snatched as she has to figure out her life as literally, a plant person alien invader, even though she's been "human" as far as she could remember (which is only since about age 3 when the person she was was eaten by an alien flower and the person she is was birthed out of that).

Overgrowth is full of gorgeous descriptions of vegetation across the spectrum (I can only imagine how hard it must have been to come up with varying ways to describe plants and plant life for 400+ pages) and more deeply, the queer experience as Anastacia herself is queer, her boyfriend is trans, and the whole plant person thing can easily be an allegory for trans existence/acceptance as well - certainly Stacia pulls the similarities more that once.

And that's what doesn't quite work, either. Overgrowth could have used a lot of editing, perhaps, or just tightening up of how often certain messages were repeated. I'd LIKE TO think (though social media often proves me wrong) that readers can get a message and internalize it without having to repeat those messages so many times, but we also live in 2025 and this book takes place in 2031 and honestly although at first it was jarring to have something set so close to today's life, a lot of the points made by the invaders are not invalid and don't seem to be clearing up anytime in the next five years (here is where I would insert a melting face emoji were I typing this on a phone). The middle really did drag for me, even when things were happening, and I think a lot of it was Stacia's internal monologue and self-justification versus self-denial especially when in-story she had too much time to think.

But then again, there were a lot of interesting things! The dream forest, the psychic pollen, the visuals of the aliens, also if I may say the gore and despair because an invasion is not a fun time, not should it be! There were also a few parts that I see other reviewers didn't like (a line about pronouns later on -- vague to save from spoilers) that I actually *did* like, even if they seemed silly or out of place from the OUTSIDE I feel like they were in line with Stacia's character and/or thought process at the time when it came to trying to mesh how these plant aliens lived with how she now had to figure out what she assumed the rest of her life might be like. And let me just say, being someone who used to cosplay for 10+ years, having Stacia's bff/roommate credited constantly as "a cosplayer" besides her actual well to do job was very funny (positive) and also like, 'Yeah! We can do a lot!'

Caitlin Kelly did a *fantastic* job with the narration, bringing to life a whole cast of characters (several of whom couldn't even speak "into the air") in a way that should always be credited as a performance over just narration. I'm not someone who's always great with audiobooks (I've been trying the last few years!) so to find one with such high tier performance is always a joy!

So overall I enjoyed this book even though it took me a while to get through and the parts I'll be thinking about are the more positive parts (especially the post-invasion-start parts really) and that's all enough to slide toward the upper rounding part of this star-rating thing.

Thank you so much to Macmillan Audio for the ALC in exchange for review!

V, except this time we are for some reason rooting for the body-snatching spore-spewing aliens.

Despite the blurb promising eldritch horror, this is relationship-focused YA Sci-Fi, which is fine if a bit misleading.

My biggest misgivings (aside from the endless repetitions, unlikable characters, shaky plot, and uneven pacing) come back to the mismatch between the positive pro-immigration trans-rights DEI messaging and the assimilating Borg-like colonizing rapacious genocidal aliens that we are asked to accept. It's like advocating for BLM with a Willie Horton poster.

What if alien plants came to earth? That's the question this book deems to answer.
I was very excited to read this, as I loved Into the Drowning Deep, also by Grant.
This was a good time. It did a good job of discussing some social commentary around citizenship and gender conformity, as well as neurodiversity. She discusses it in an accessible way, without beating you over the head with it, so I believe that it is effective.
The narrator did a great job, and the science of this is also very palatable. Some really great body horror as well. The only thing that I struggled with was the length and the pacing. I feel like Grant spent a lot of time showing us the same things and adding length to the book where it wasn't strictly necessary for the reader to go over those things multiple times. It started to drag out at the 75% mark. If some parts had been cut I think it would have been more effective.
Overall it was a good story and if you like science fiction horror I would tell you to absolutely give this book a read.

When Anastasia Miller was three year old, she wandered into the forest, and something else wandered out. Since then, she’s been telling everyone she’s the vanguard of an alien invasion, even if no one believes her. Now, thirty years later, an alien signal has been broadcast around the world, and Anastasia knows she wasn’t lying. But she’ll have to decide which side of the inevitable war she’ll be on - with those who birthed her or those who raised her.

This book was definitely not what I was expecting, but I still really enjoyed it. I thought it was going to be more Invasion of the Body Snatchers meets War of the Worlds, but the story focuses more on Anastasia and the humans her have essentially become her family than on the actual invasion.

While there were some creepy alien bits (the story starts out with a child being murdered by a plant from outer space), it also included some pretty heavy themes that really make the reader think. As the invasion finally begins, Anastasia realizes she's going to have to choose whether to support the species she's known her entire life or let the species she comes from eat most of the human race. On the flip side, her friends and long-term boyfriend have to decide whether to support humanity or allow an alien species to transform them. This raises the question of whether or not they'll still be them on the other side of that transformation.

I listened to this one on audio, narrated by Caitlin Kelly, and she knocked it out of the park. The story is told from Anastasia's POV, and Caitlin does a great job creating unique voices for all of the characters, including the aliens introduced during the invasion.

Read if you like:
Sci-fi horror
Body snatchers
Apocalyptic
Found family
30s FMC
Queer rep
Thought-provoking

Anastasia has been telling anyone that would listen she’s an alien from an invading species, but no one would listen. Now the aliens are here and the humans are realizing that they really should have listened to the warnings…


An alien invasion told through the POV of the alien? Sign me up. It was such a fun and original take on a scifi story. I do wish we saw a bit more of the invasion. I also loved the found family aspect of this story. There’s nothing better than a group of friends that become more. There were times when this book had me laughing out loud.


While I enjoyed the concept and characters in this story, the pacing dragged and the ideas became repetitive. This book is a slow burn, if you’re only here for the invasion, you’re going to be waiting. While you’re waiting, you’ll be with Stasia as she has the same inner monologue over and over.


If you’re in the mood for a quirky Little Shop of Horrors meets Independence Day horror/scifi, I recommend the audio. The narrator does a great job in bringing Stasia to life and holding your interest. Thank you to @macmillan.audio and @netgalley for my copy!

This started out strong but unfortunately lost momentum as it went.

We follow Anastasia, a woman who is convinced that she is the vanguard of an alien species who is going to invade the planet. After a scientist intercepts a signal from space, it turns out Anastasia had been right all along. We follow her, her boyfriend Graham, and their friends as they attempt to stop the end of the world.

The first 25% of this book was very good. I liked Anastasia as a character and following her through the beginning of the invasion was interesting. However, this book is almost 500 pages, and that is entirely too long. It got slow and repetitive very quickly. It could have been half the length and been a great novel. While killer alien plants is a good premise, the execution left me ultimately unimpressed.

The best part for me was the narration. I could absolutely picture Anastasia talking like this.

4.5 stars

I received an advance audiobook copy of Overgrowth by Mira Grant from netgalley.

This isn't my typical genre, but I was hooked from the start.

The narration is well done.

The characters, settings, and events are well described. The storyline is fast paced. A fun read.

Definitely recommend.

Overgrown is at its heart a science fiction novel about identity. Who we claim as “ours” and who we shun as different.

The book opens with the brutal body-snatching murder of a small child. The child is replaced by an alien. We follow this replacement into their 30’s, and the eventually alien invasion that their “birth” caused.

I had mixed feelings, but by the end of this I just wasn’t sold.

That being said: if you read this you will get to experience a polyamorous plant dragon. So there’s that.

GOOD:
On the one hand, this book had some of the most lush and beautiful descriptions I’ve read in a novel in a while. The imagery was at times spectacular and ethereal and genuinely magical. It also is a fascinating concept that has so much going for it. This authors overall plot itself is engaging. Plants coming to eat the human race? Sign me up bro. The main characters voice is (mostly) incredibly engaging (until the end) and many of the side characters fill perfect roles within this type of literary fiction. (Love you Tony). It is, at times, disgusting to read, causing visceral reactions, which drew me into the otherworldly tone. The overall vibe is immaculate. All of this worked to propel me really well through most the book.

Also, give the audiobook narrator a raise. She KILLED that shit. Like truly, that helped with a lot of the issues I’m about to address so much. (I worry a little about how all this will come off in print).

Also some of the human character villains were such wonderful archetypes. The one NASA lady…lovely. Hated her.

STRUGGLED WITH SPECIFICS:
Now on the other, the pacing is really off (which many reviewers have noted). It drags at times particularly in the middle and you have to stick it out to the ending for the big pay off. This stems from two things.

1) this author clearly doesn’t trust their audience to “get” the message. It is repeatedly bashed over our heads. Like girl, I am all for exploring living as a trans person through science fiction but please don’t bring it up every other paragraph (subtly and not subtly) and go into it over and over in depth. I get it. I’m on your side already. Please just get to the alien invasion. Better yet, let the themes of the story become clear through the actual alien invasion rather than just repeatedly telling us.

And 2) the continued and repetitive interiority of the MC. So much interiority. So much of it repetitive. How many times do I have to read “I knew by some deep instinct…”

Actually maybe that’s just the same point. The author needed to make their “point” and didn’t trust us to get it. And it bogged the book down.

(Minor thing: the characters were supposed to be in their thirties…but felt much younger).

(Also I saw other review that said something along the lines of “it doesn’t feel productive make the trans alien character a child murderer…” which like…actually good point…)

That being said, the examination of transness/otherness through science fiction is crucial work and I think this book adds to a long line of sci-fi pushing the boundaries of gender. The Left Hand of Darkness comes to mind for me.

QUESTIONS:
I am genuinely confused on how I am supposed to read Anastasia. Are we supposed to read her as a problematic MC who slowly becomes a colonizer? (Because coming to a planet and killing all the native people because they aren’t “good enough” is giving heavy colonizer energy…) OR Are we supposed to read her as positive, making the end message that in order for the world to be better we have to literally kill everyone except for those who are politically left? (Which feels almost like a Babel argument, but way less well executed?)

If we are meant to read her as problematic, an untrustworthy narrator, then her siding with trans people and the left makes this book feel VERY icky to me.

If she’s positive, I guess I can see how the argument is that the world needs to be remade into a more accepting place and that sometimes that takes violence, but she literally forces her boyfriend to change for her entirely. The aliens literally murder billions of people? How am I supposed to truly get behind that? Am I being plantist right now?

FINAL:
As I wrote this review, I realize I didn’t really like this book at all. It was so heavy handed. And the final message doesn’t sit right with me.

Anastasia Miller is an alien, and she knows she's an alien, and she's told everyone she knows since she's a child that she's an alien. She went into the woods as a normal healthy child, lost consciousness, and when she woke up - she suddenly knew the truth. But she's lived a human life with human friends and a human boyfriend - and a cat.

Until she hears a signal that she knows is from her home planet, which means they are finally coming. And they're probably not coming in peace. Anastasia finds herself caught between her human and alien selves.

I have mixed thoughts about this book. There were parts of this book, especially in the middle, that I really liked. There were also some parts that seemed juvenile and silly. So overall I'll put it about 3.5.

thank you netgalley for giving me an advanced review copy of this audiobook

Overgrowth starts off with a bang—creepy, unsettling, and undeniably intriguing. We meet Anastasia “Stasia” Miller, who wanders into the woods at age three, touches a strange alien plant… and doesn’t come back the same. Ever since, she’s insisted she’s an alien—no one believes her, of course. Until Earth starts receiving messages from deep space, and suddenly, everything Stasia’s said doesn’t sound so crazy anymore.

Told from Stasia’s POV, this is a strange and thought-provoking story of identity, alien invasion, found family, and what it means to truly belong. It blends cozy sci-fi with horror elements, social commentary, and some emotional character moments—especially early on. I loved the first half of the book, especially the exploration of Stasia's alien perspective while trying to live among humans, her quirky circle of friends, and the slow-building tension of an invasion hiding in plain sight.

But then… it lost me. Somewhere past the halfway mark, the tone shifted dramatically. What started as eerie and emotionally rich morphed into something chaotic, preachy, and hard to follow. The pacing dragged early on, only to suddenly rush through major events and throw in info-dumps and over-explained metaphors. What could’ve been powerful themes around identity, queerness, and otherness felt clunky and forced, instead of naturally integrated into the story. At times, it felt like the message overwhelmed the narrative itself.

By the end, I wasn’t even sure what kind of story it was trying to be. The plot twisted itself into something so far removed from the engaging setup that I struggled to stay connected. The alien mythology, the stakes of the invasion, and even the characters I once liked started to feel like afterthoughts.

That said—the audiobook is fantastic. Caitlin Kelly’s narration is phenomenal and honestly kept me going when I was tempted to stop. Her performance alone is a 5-star experience.

Final thoughts: Overgrowth has some truly fascinating ideas and moments that shine, especially early on. But inconsistent tone, uneven pacing, and heavy-handed messaging ultimately pulled me out of the story. I’m glad I gave it a shot, and I’ll continue reading Mira Grant—but this one left me feeling more wilted than wowed.

Thank you NetGalley, the publisher, and the author for this ALC in exchange for an honest review!

2.5 stars. Mira Grant/Seanan McGuire is always a hit or miss author for me and unfortunately, this one was a miss. It just was very repetitive and it didn't hold my attention very well.