Quick Synopsis – When Ruby Young discovered that her Boston apartment was haunted, she did what any reasonable person would do: befriend the ghost. Their relationship overcame a shaky start—Cordelia Graves never wanted a roommate in life, she certainly didn’t want one in death. After working together to solve a few murders, the two are close friends, but there’s a lingering question neither of them have been able to answer: what led to Cordelia’s death?

Lately things have been adding up that suggest foul play. And when Cordelia’s memories of that day start to come back, the roommates can’t ignore it anymore: Cordelia was murdered. Ruby and Cordelia are going to have to piece together what Cordelia’s final days looked like—otherwise a killer could go free.

Song This Reminds Me Of – Closer by Nine Inch Nails

Publication Date – Oct. 20, 2026

Bookshop Link – The Key to a Killer by Olivia Blacke
I receive a small commission if you order using my link

Content Notes – There are several mentions of alcoholism and alcohol abuse. There are flashbacks to child neglect, an alcoholic parent, and death of a parent. There is some violence and blood.

Rating – ⭐⭐out of 5

Review – This is the third book in the series, don’t read this review because there could be minor spoilers. I liked the other two books in this series, but this one just didn’t vibe with me. Most of the book is spent rehashing what we already know from the other books. I felt like I was skipping pages just to get to the plot of this book. When we finally start uncovering more plot, it feels incredibly rushed. I like a good red herring, but this felt like the author threw a twist in there just for fun. It’s like a Marvel movie, they don’t want you to guess the spoiler, so they just make something up that’s crazy. I feel like it’s better storytelling when you can follow the plot to a logical conclusion, instead of a c plot coming out of nowhere to slap you in the face.

The plot of this book is supposed to be following how Cordelia really died. Again, so much of Cordelia and Ruby investigating in this book is really just rehashing the last two books. I found myself flipping through pages, just wanting to get to the big reveal. I could have done with more character development for Cordelia’s brother and Tosh, Ruby’s kind of love interest. There was more Cordelia and Adam (Cordelia’s old boss and married lover) backstory revealed, and Cordelia gets more of her memories back from the events leading up to her death. I still felt like these parts were rushed and too much of the book was just filler.

The last act of the book just felt like an accident. There is a running plot throughout this book about burglaries in the building Ruby/Cordelia live in. While Ruby is sort of investigating this, it seems like it would have been easily solved if Cordelia, you know the ghost, would have just staked out the hallways to catch the perp. I just wasn’t satisfied with how the plot rolled out. I will likely read the next in the series and I hope it’s more satisfying than this.

Thanks to NetGalley and Minotaur for the advanced copy, all opinions are my own.