Glenn Cooper is an excellent writer.
The plot moves from Hiram Donovan's death to his son, Cal, thirty years later. All is certainly not what it seems when Cal discovers a black obsidian mirror, which is the showstone.
Cal investigates the murder of his mother.
I don't want to give more away at this point as it would spoil the novel, but later chapters involve Doctor Dee, who lived in Elizabethan times and Elizabeth's spymaster, Walsingham.
An amazingly good plot and all the characters are well drawn.
I would highly recommend this book to readers who like a novel where magic is accepted as real. And the chapters dealing with Dee are interesting for an historical viewpoint, so I would also recommend the novel to readers who enjoy historical fiction.

Good plot! Wry interesting and done will in my opinion. It was a good read, but not for me at this time. I can’t deny that it was a good read overall though.

A Layered Thriller with Multiple Perspectives

This was my second Glenn Cooper novel. The Showstone continues his style of writing thrillers that set themselves apart. The premise is intriguing and gives the mystery a strong foundation, blending suspense with deeper historical and moral undertones.

What kept it engaging was how Cooper shifts between multiple perspectives and moves back and forth in time. Those transitions provide context while keeping the pace moving and the bigger picture unfolding.

There’s a solid mix of characters, and the main ones develop enough that their motivations and internal conflicts feel believable. While a few plot developments push the edge of realism, they add to the intrigue rather than detract from it. Overall, it’s a compelling, well-structured thriller that balances suspense with thoughtful storytelling.

368 pages

4 stars

This book is a great entry into the Cal Donovan series. The storyline is unique and interesting. I found it to have a touch of the supernatural with religious overtones. I truly enjoyed the characters and their motivations.

The scryers as described in the novel are those who can see and speak to angels in a special language. The scrying is facilitated by a “showstone.” This can be a special object, such as a stone, or water, or even a hallucination.

The push-pull between the tendency to do good versus evil is a major theme. The human need for revenge, also played a part in the motivations of certain characters

The plot is a tense, action-packed race to locate and obtain an obsidian showstone found and subsequently looted by Cal’s father, Hiram. One man is determined to obtain it to further his own ends.

I want to thank NetGalley and Book Whisperer for forwarding to me a copy of this book. The opinions expressed in the review are solely my own.

The Showstone blends historical intrigue with modern suspense in a way that feels immersive and deliberate. Glenn Cooper once again leans into layered storytelling, weaving together past and present to explore how knowledge, especially forbidden or hidden knowledge, can shape destiny. The novel carries a strong sense of intellectual mystery while still delivering the tension expected from a thriller.

What stood out most to me was the concept at the heart of the story. The idea of a mysterious object with deep historical roots creates immediate intrigue, and Cooper uses it effectively to anchor both the plot and the thematic core. The historical elements feel researched and purposeful rather than decorative. They add weight to the narrative and reinforce the sense that the present is always entangled with the past.

The pacing is steady and confident. There are moments of high tension balanced with quieter sections that allow the reader to absorb the implications of what is unfolding. The emotional stakes build gradually, especially as the characters begin to understand the consequences of what they are dealing with. While a few transitions between timelines may require close attention, they ultimately contribute to the layered structure of the novel.

The Showstone delivers a thoughtful, suspense driven reading experience. It will especially appeal to readers who enjoy mysteries grounded in historical depth and philosophical undertones.

Glenn Cooper has done it again! The Showstone is part of the Cal Donovan Vatican Conspiracy Thriller series. This novel is based on a stone (believed to be a showstone) that is discovered during an archeologist dig in Iraq in 1988 by Cal’s father Hiram Donovan who was a professor at Harvard before his death. Hiram smuggles the stone out of Iraq before his murder. Along with the stone are pieces of papyrus with writing. Could this writing be connected to the stone and thought by believers that it is a way to speak with angles? Thirty years after the stone is uncovered and thought lost, a deathbed confession reopens the search and along the way bodies are piling up. I don’t want to give away too much but let’s just say the ride is very entertaining with twists and turns and lots of action. Cooper’s writing takes you to the past where this showstone was used by John Dee and Edward Kelly in an attempt to communicate with angles through scrying and then the next chapter brings you to the present day with followers of the Enochian magic that are searching for the ability to reach the 49th call. By the end of the novel Cooper has tied all the pieces together and shows you how they all fit. A great read that I had a hard time putting down.

Thank you NetGalley, Book Whisperer and Glenn Cooper for this advance reader copy for a review.

A well written narrative, plunging into the depths of age old history, religious beliefs, scrying and murder. Cal finds himself in the midst of it all as he discovers that the not so accidental death of his father, is where it all began. Very in-depth and an excellent read. I received an ARC from Book Whisperer/Netgalley and I am leaving this review voluntarily.

I thank the publisher Book Whisperer for access to this book. I also thank NetGalley for this book.

I have been a fan of Glenn Cooper’s books for a while now, especially the Cal Donovan series. I have read the previous books featuring this character and have always enjoyed the blend of history, mystery and fast paced storytelling that Glenn brings to his thrillers. So when I saw The Showstone available as an ARC on NetGalley, I was genuinely excited to pick it up. It was easily one of my anticipated reads because I was curious to see where Cal Donovan’s story would go next.

For readers who are already familiar with the series, Cal Donovan is a Harvard professor whose academic life often pulls him into mysteries connected to history, religion, and hidden secrets. In this book the story becomes more personal. Years earlier Cal’s father discovered a strange obsidian stone during an archaeological excavation in Iraq. Recognizing that the artifact might be important, he secretly sent it home before he died under suspicious circumstances. Many years later Cal’s mother also dies in what appears to be a tragic incident, but the reappearance of the same mysterious stone suggests there is far more going on beneath the surface.

The artifact at the heart of the novel is known as a showstone, an object historically associated with visions and scrying. Glenn builds an intriguing narrative around the possibility that such an artifact might hold a power people have sought for centuries. As Cal begins to uncover the truth about the stone, he also starts to unravel secrets connected to his own family and to a much larger mystery that stretches across time.

One of the things I have always enjoyed about this series is how Glenn mixes historical elements with a modern thriller storyline, and The Showstone continues that tradition. The book moves between past and present as the history of the stone is slowly revealed. These historical glimpses add depth to the story and make the mystery feel much bigger than the immediate events surrounding Cal.

The pacing is also very strong. The chapters move quickly and the story keeps introducing new clues and revelations that push the mystery forward. It is one of those books that is very easy to keep reading because the tension builds steadily and you always want to know what the next piece of the puzzle will be.

But, there were also several moments across the book where the story felt a little familiar in terms of thriller tropes, especially if you read a lot in this genre and also some collected baggage from the series which regular readers would find repetitive. I also would have liked a little more character exploration in certain sections, particularly given the personal connection Cal has to the central mystery.

Still, as someone who enjoys Glenn’s writing and the Cal Donovan series, I found this to be a very satisfying read. It delivers the kind of historical intrigue, mysterious artifact and unfolding conspiracy that I expect from this author.

Overall, The Showstone was a very enjoyable continuation of the series and one I am glad I had the chance to read early as an ARC.

Four stars. A fast paced and intriguing thriller that will definitely appeal to fans of the Cal Donovan series.

4.5 ⭐️

Thank you NetGalley for this Arc.
This was an engaging book with blend of historical mystery, archaeology and occult intrigue.
Loved how the story paced forward and the different timelines were definitely a good addition.
I couldn’t keep this book down. Read it in one day.