Review: Into the Drowning Deep

Title: Into The Drowning Deep
Author: Mira Grant
Age-range/genre: Adult / Sci-Fi, Horror
Trigger warnings: death, gore, medical content, references to homophobia.
Rating: 4.5/5 stars
Summary: [from goodreads]

Seven years ago, the Atargatis set off on a voyage to the Mariana Trench to film a “mockumentary” bringing to life ancient sea creatures of legend. It was lost at sea with all hands. Some have called it a hoax; others have called it a maritime tragedy.

Now, a new crew has been assembled. But this time they’re not out to entertain. Some seek to validate their life’s work. Some seek the greatest hunt of all. Some seek the truth. But for the ambitious young scientist Victoria Stewart this is a voyage to uncover the fate of the sister she lost.

Whatever the truth may be, it will only be found below the waves. But the secrets of the deep come with a price.

Rating: 4.5 out of 5.

recommended for: fans of sci-fi & thrillers, killer mermaids, and cozy horror novels

A fun mix of sci-fi fantasy and thriller, Into the Drowning Deep is a riveting novel that’s hard to put down.


“As long as there was life in the sea, there would be teeth.”



This novel had been on my tbr for two years, but for the life of me I could not get through the ebook. Borrowing the paperback was the best idea; the paragraphs that I initially thought were chunky in the ebook were so easy to breeze through in the physical copy.

A short summary: Into the Drowning Deep takes place following a maritime tragedy, where a voyage to the Mariana Trench ended in bloodshed with no survivors. The culprit? The main theory is mermaids. Now, years on, Tory is determined to find out the truth of what happened to her sister, who had been on that original voyage. She is invited to join the new crew who are taking the same journey, and she is ready to help them seek the truth.

Firstly, can I just say, I absolutely love the concept of killer mermaids/sirens! I love the idea of these beautiful alluring creatures being able to lure people to their deaths. In this novel, despite the fact that no one has really seen these mermaids, or are aware of what they really look like (they later find out they are more amphibian in looks than a pretty human), the mermaids are still able to lure in prey to devour. They are described so vividly that I was about as fascinated and terrified as the scientists themselves.

With a plethora of characters, and a terrifying setting in the middle of the ocean, Grant is able to create a fascinating story about science and horror. It’s surprising how well Grant is able to develop all the characters in only 500~ pages. All the characters have different goals in mind, and different reasons for why they are on the search for mermaids. And the mermaids themselves are so fascinating and terrifying to read about, and they had me on edge for half of the novel.

I am not the first to chase the mermaid from sea to sea […] I am just the most recent of a long list of Cassandras looking at the waves and saying “this is not for us.”


characters & romance

Tory, the first main character we are introduced to, has a simple enough goal: to find out what killed her sister in the last voyage searching for mermaids. She just wants that closure, and has landed herself on this cruise just for that. For other characters, it is less of a personal attachment and more so the hunt to find out more, or for fame and glory in a new discovery, or just to know the truth on if mermaids are actually real. I enjoyed how all the characters were set apart in their goals, and seeing the turmoil that it created. 

It’s difficult to pick a favourite character because I thought they were all so interesting and multifaceted. One of my favourites was Dr Toth. She has been a long time believer of mermaids, despite so many of her colleagues looking down on her research. However, when push came to shove and there was real danger, she didn’t let her arrogance and ambition blind her; she knew when she had to get out, and was determined to make it out alive.

There’s also a bit of romance, which I enjoyed! It was so lovely being able to read a sapphic romance with a woman from STEM, and an autistic female character – it’s so rare to see this representation, so it made me so happy to see.

“The trouble with discovery is that it goes two ways. For you to find something, that thing must also find you.”


ethics and science

There is a lot of faux-science talk in the novel as they discuss research and evidence. It adds an element of realism to the story, though I am sure that a lot of it is completely made up pseudo-science. It was still fun to read, and reminded us that these characters are educated scientists, juxtaposing their naivety that this will be a harmless cruise with hardly any danger.

A theme throughout the novel is the lengths science will go in the name of research. This is the second time a voyage to find mermaids has been undertaken; the first one ended in bloodshed, with no survivors. And yet, despite this, it is decided another voyage is a great idea. The thirst for knowledge is understandable, but at what cost? 


Overall, Into the Drowning Deep is a fun novel that delves into themes of science and morality, alongside having lots of action involving killer mermaids in a thrilling survival story.


Thank you for reading!
Let me know if you have any sci-fi/horror recs!


11 thoughts on “Review: Into the Drowning Deep

  1. Great review! I hadn’t heard about this book before and it sounds like an amazing read! I feel like I need it in my life now (although I haven’t read much horror before, so that does make me a bit hesitant 😅)

    Liked by 1 person

  2. I’d seen this book around & ever time I see the cover it makes me want to read it, really enjoyed reading your thoughts Saima! I like the element of the spooky blended with science, I rarely read mermaid stories but I’m interested to see how they are explored in this one. Also agreed, reading a book physically makes the experience more of a breeze! 🤩

    Liked by 1 person

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