The Key to a Killer by Olivia Blacke Review: Ruby and Cordelia Mysteries #3

ARC by NetGalley📱📖 Read on Kindle
📃 368 pages | ⏱ Duration: 4 hours
Genre: Paranormal Cozy Mystery
🏷️ Publisher name: Minotaur Books
📅 Publication date: October 20, 2026

Book blurb:

When Ruby Young discovered her Boston apartment was haunted, she did what any reasonable person would do and befriended the ghost. Cordelia Graves never wanted a roommate in life, and she certainly didn’t want one in death, but after solving a few murders together the two are close friends. One question still hangs over them, though: what led to Cordelia’s death? Clues pointing to foul play keep adding up, and Cordelia’s memories of that day are returning. Now the roommates have to piece together her final days, or a killer could go free.

Let’s talk about the book:

Ruby and Cordy are simply a joy to spend time with. By this third book, Ruby has grown into herself. She is less shy and far more willing to be blunt with Cordy, and that growth gives the friendship more depth and the banter more bite. I enjoyed the dynamic more than ever.

This installment is also the most personal for the series, as the central mystery of how Cordelia died takes center stage. It brings to a close the arcs that have run through the previous two books: the question of Cordy’s death and the leaked secrets at TrendCelerate. Long-time readers will appreciate the payoff.

Ian remains as frustrating here as in the earlier books, but his love for his sister shines through. Given everything Cordy does for him in this installment (no spoilers!), I’m hoping he finally becomes the reliable brother she deserves.

Blacke has a real talent for world-building. Her characters feel so believable that you root for them as if they were people you know. My one reservation is how the TrendCelerate leak was resolved. After two books of build-up, the resolution felt underwhelming, and I had hoped for a stronger payoff. It was the only thing that didn’t fully work for me.

With the main mysteries now solved, I hope the series continues. I’m not ready to say goodbye to Ruby and Cordy, and I’ll admit, somewhat grudgingly, that I’m curious what Ian will get up to next.

Would I recommend it?

If you have followed Ruby and Cordy from the beginning, The Key to a Killer is the one you have been waiting for. The mystery of how Cordelia died finally takes center stage, and the friendship between the two has more bite than ever. The TrendCelerate resolution felt underwhelming after two books of build-up, but I still had a great time. This is a series I am not ready to leave. It publishes on October 20, 2026, so add it to your TBR and mark the date in your calendar.

⭐⭐⭐⭐

Keep the Spirits Up

• A New Lease on Death by Olivia Blacke
  New to the series? Start here, where Ruby moves into a Boston apartment that already has a ghost living in it.

Indiebookstores.ca | Bookshop.org | Goodreads | StoryGraph | Pagebound | Fable | Hardcover | Booktrovert | OpenLibrary | Litsy

• Vinyl Resting Place by Olivia Blacke
  Same author, cozier side, where three sisters find out that opening a family record shop can be murder.

Indiebookstores.ca | Bookshop.org | Goodreads | StoryGraph | Pagebound | Fable | Hardcover | Booktrovert | OpenLibrary | Litsy

• Curiosity Thrilled the Cat by Sofie Kelly
  If you like your cozies with a touch of the unexplained, the first Magical Cats mystery gives you Kathleen and two cats with opinions about everything.

Indiebookstores.ca | Bookshop.org | Goodreads | StoryGraph | Pagebound | Fable | Hardcover | Booktrovert | OpenLibrary | Litsy

• Ghost at Work by Carolyn Hart
  Bailey Ruth Raeburn is a ghost who returns to earth to help the living with a murder, so it scratches the same itch as Ruby and Cordy.

Indiebookstores.ca | Bookshop.org | Goodreads | StoryGraph | Pagebound | Fable | Hardcover | Booktrovert | OpenLibrary | Litsy

• A Pinch of Magic by Emily Heil
  A cookbook ghostwriter accidentally summons a ghost from an old cookbook and has to help right a century-old wrong. It’s a cozy paranormal with small-town charm.

Indiebookstores.ca | Bookshop.org | Goodreads | StoryGraph | Pagebound | Fable | Hardcover | Booktrovert

Would You Befriend the Ghost?

Ruby found out her apartment was haunted and decided to make friends with the ghost. Would you have done the same, or would you have been out the door with your bags packed? If you have read the series, did you guess what happened to Cordelia before the reveal? And where do you stand on Ian, hopeless case or still redeemable? Tell me in the comments.

Book Links

Want to purchase this or any of your favorite books while supporting a local bookstore? Consider purchasing using the sites below. These sites work with independent local bookstore owners to fulfill your book orders. #SupportLocal

Indiebookstores.ca | Bookshop.org | Goodreads | StoryGraph | Hardcover | Booktrovert
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