Cold Blooded Killer: A Review of What Darkness Does by Jennifer Graeser Dornbush

Hello, Book Nerds! Welcome back to Reading Has Ruined My Life or welcome if you are new. As always, my name is Hannah and I am your captain on this journey into my bookcases.

I have a very special review for you today, Book Nerds. Today’s review is brought to you by Blackstone Publishing. They aren’t paying me for my review, they just sent me the book for free; all thoughts and opinions are my own. Thank you very much to Blackstone Publishing for offering me a copy of today’s read. It really does mean a lot to me anytime someone out there offers me books. Thank you, thank you! And what title was I so kindly sent?

Please give a warm welcome to What Darkness Does by Jennifer Graeser Dornbush! What Darkness Does is the latest entry to The Coroner’s Daughter mystery series and released on October 28, 2025.

Let’s get to the synopsis now, shall we? As always, a spoiler alert is in order. If you’ve read any other review on the site then you will know I simply love to spoil the entirety of the books I read. This is your one and only warning. I also have a content and trigger warning to give before we crack in. What Darkness Does deals heavily with sexual assault and rape. There is also child endangerment. One of the main plot lines is about a missing baby. Please release the breath I know you are holding, dear reader, the baby is ultimately fine. Finally, this book touches on PTSD and abuse. These topics are all extremely prevalent to the plot and cannot be avoided; please take care while reading. With that, let’s crack in.

In the latest entry of The Coroner’s Daughter series, Dr. Emily Hartford is called to the hidden gem that is Lake Isabella in Freeport county where the body of Savannah Browdey is found. Savannah was discovered by two highschoolers who were skipping class, and she was very obviously murdered as she was bound and gagged before being tied to a cinderblock and thrown into the lake. Her killer clearly wanted her to disappear forever.

Yeah...this is a pretty dark crime.

The case manages to get worse as Savannah was last seen with her baby daughter Brooklyn. But Brooklyn is nowhere to be seen. That’s right, there’s a missing child. Then more and more bodies turn up in relation to this case. Yeah…this baby was taken by a serial killer. Wait! It still gets worse as the villain is killing all these people to evade rape charges! This is a jam packed crime book.

Still there is more as Emily’s former lover, her almost fiancé, has returned. FBI agent Nick Larsen turned up at the end of Frozen Lives after he was presumed dead. He was actually being held captive overseas for organ harvesting, but managed to escape and return home. Now Emily is going through many, many emotions as she and Nick navigate their relationship. Speaking of Nick, he decides the best form of therapy is putting the villain of the story behind bars. He has not been cleared for work, yet he forces his way into helping solve the case.

For a story with such high stakes, I found none of the characters show their concern for baby Brooklyn’s safety. Often times a character will express concern for the child, yet they don’t show said concern. There’s not much rushing around and chasing down every lead. I found the characters too calm at times. Perhaps this issue is occurring because Emily is the main character of the series and she is the medical examiner. She’s not the lead detective, she’s not even a detective, therefore she’s not the one who is running around and chasing every lead. As the focus is on her for the vast majority of the book, the concern for the missing child is not able to be properly shown; which is a major issue given the stakes of the novel.

Another issue I had with the book, and this is more a personal issue as opposed to an actual issue with the writing and quality of the novel, is the backstory of various characters. What Darkness Does is book five in The Coroner’s Daughter series. I have never read any other book in the series. While I found the crime and mystery aspect easy to follow and understand, I was very clearly missing big parts of the series. Namely everything to do with Nick Larsen and his relationship with Emily. I got the basics. I know they were deeply, madly in love before he disappeared while on the job. I understood she was grieving him as he was dead. But all the details in-between are missing. Their story is far from complete. I fear my lack of knowledge on their relationship and struggles deters from both my understanding of them as characters and their relationship, thus my enjoyment of the book is decreased.

What Darkness Does is not without merits. The relationship between Emily and her niece Flora is a major highlight for me. Flora takes such interest in forensics which Emily eagerly fosters by allowing her to sit in on autopsies and taking her to science camp. Their relationship very much proves that raising a child takes a village. It’s such a wholesome, trusting, and loving dynamic between niece and aunt that I can’t help but adore it.

Claps for this wholesome family dynamic.

And keeping with the characters, Jennifer Graeser Dornbush created one of the most terrifying villains I’ve seen in a while. The villain is real. He was based off a real-life serial killer, and even if he wasn’t, I know without a shadow of doubt that this man could exist in real life. This villain is a disturbing, violent individual who I hate with every fiber of my being. My skin crawled every time I had to read about him. I wanted to punch him in the face, I wanted to fight him. I had a visceral reaction every time he appeared. I can’t help but applaud the author in her creation of this absolute shit stain of an antagonist.

Overall I enjoyed reading What Darkness Does. I very much missed things during my read having never read any other book in the series, but it does work well enough as a stand-alone. The characters are well developed, as are their relationships, and the stakes of the mystery are high even though I question their level of concern at times. Though, if you have read the rest of The Coroner’s Daughter series I do believe you will greatly enjoy the latest entry.     

Thank you once again to Blackstone Publishing for sending me a copy of today’s book. I greatly appreciate you sending me a new read. Thank you, thank you!

And with that, I shall bid you all adieu, Book Nerds. I will see you all again next week with another new review. If you can’t wait that long then I highly suggest giving Reading Has Ruined My Life a follow over on Instagram (@ReadingHasRuinedMyLife). You can also follow the blog on Twitter and BlueSky (@RHRMLBlog). If you want something not related to books, then may I suggest checking out my podcast Nothing to See Hear. The show stars me and two of my dearest friends as we talk about everything and anything. My recommendation this week is our Weird Moments in History playlist. History is cool, and also very weird. You can find the show on Spotify and YouTube.

Until next time, stay safe, wash your hands, and read some good books for me.

See y'all then, bye!