Covenant of the Dead

by Glenn Cooper

Genres: Thriller, Fiction, Mystery

384 pages, Kindle Edition

Published March 26, 2026

About the author

Glenn Cooper is an internationally bestselling thriller writer.

Glenn was born in New York City and grew up in nearby White Plains. He attended White Plains High School before enrolling at Harvard University in Cambridge, Massachusetts where he graduated from Harvard with an honors degree in archaeology. He then attended Tufts University School of Medicine and did his post-doctoral training at the New England Deaconess and the Massachusetts General Hospitals becoming a board-certified specialist in Internal Medicine and Infectious Diseases. After practicing medicine, Glenn began a research career in the pharmaceutical industry which culminated in an eighteen-year position as the Chairman and CEO of a biotechnology company in Massachusetts. Glenn began writing screenplays over twenty years ago and his interest in movies prompted him to attend the graduate program in film production at Boston University. He is currently the chairman of a media company, Lascaux Media, which has produced three independent feature-length films. In 2006 Glenn turned his hand to novel-writing. His debut novel, THE LIBRARY OF THE DEAD, the first in a trilogy, became an international bestseller and was translated into thirty languages. All of his seven published books have become top-ten international best-sellers.

Glenn currently lives in New Hampshire.

Reviews

[Anne · Rating 5 out of 5]

Covenant of the Dead by Glenn Cooper is another semi-religious mystery featuring Cal Donovan, a tenured professor in Harvard’s Divinity school who has, to cap off all his deeds, fallen in love with a nun. Not just any nun, but perhaps the most famous in the world: Elisabetta Celestino, the former Secretary of State for the Vatican. Many changes have to happen before they can be together, not the least of which, Cal has to stop drinking, which is no small thing, but appears to be happening. She has joined the staff at Harvard and is a natural teacher, until three nuns are murdered and a column comes out in the newspaper in which a medium appears to identify the killer. Her curiosity is piqued and she convinces Cal to join her in a sitting (séance) where she hears an unlikely message from her brother. Upon investigating, she discovers it to be true and she is beyond torn. The investigation into the murders continues with much of it historical, as is the practice of mysticism.

This series is full of intriguing plots, and twists and turns that not only engage the mind, but force the reader to re-examine their own beliefs. Cal has always been an engaging character, smarter than he has any business being, and finds himself embroiled in interesting situations. Elisabetta is an intelligent woman, a consummate politician, and so much more, it turns out. The book embraces the topic of the psychic world in which many have participated, including Sir Arthur Conan Doyle of Sherlock Holmes fame. Delving into the past is a hallmark of Cooper’s series. I find his books, not only educational, but interesting and compelling. Great read.

I was invited to read Covenant of the Dead by Book Whisperer. All thoughts and opinions are mine. #Netgalley #BookWhisperer #GlennCooper #CovenantOfTheDead

[BookishDramas · Rating 4 out of 5]

I read this book as an ARC from NetGalley and this review is based on my reading the book and is an honest feedback about the book.

Any new Glenn Cooper release automatically goes to the top of my list. Having read multiple books by the author and followed the Cal Donovan series closely, I fully expected a clever mix of history, mystery and suspense. I am happy to say this one delivers exactly that, with a darker and more atmospheric edge. The presence of Arthur Conan Doyle as an important character in the story creates an even cooler mix.

The story begins with a brutal and unsettling crime inside a Boston convent. Three nuns are murdered under strange circumstances and the only clue is that their rosaries are missing. From there, the narrative opens up into a layered investigation that brings Cal Donovan and Elisabetta Celestino into a world of séances, mediums and the lingering question of whether something beyond logic is at play.

One thing I always appreciate about Glenn’s writing is how effortlessly he blends historical detail with a fast moving thriller. The inclusion of spiritualism and its historical roots adds an extra dimension to the story and keeps things intellectually engaging. It is not just about solving a crime, it is about understanding belief, doubt and how far people are willing to go for both.

Cal Donovan remains a character I enjoy returning to. There is a familiarity there that long time readers will appreciate and his dynamic with Elisabetta continues to work well. Their interactions feel natural and grounded, which helps balance the more eerie and ambiguous elements of the plot.

The pacing is strong for the most part, especially in the opening and closing sections. The middle does slow down slightly with more focus on background and explanation, but it never loses my interest. If anything, it adds depth even if it softens the tension a little.

What stood out most for me was the tone. This is a darker story compared to some of Glenn’s earlier work. There is a constant sense of unease that builds steadily and leads to a satisfying and impactful conclusion. The ambiguity surrounding the supernatural elements is handled well, though readers looking for clear answers might feel slightly conflicted.

Overall, this is a solid addition to the series and another reminder of why I keep coming back to Glenn Cooper’s books. It may not be my absolute favorite from him, but it is definitely a compelling and enjoyable read that I would recommend to fans of historical thrillers with a touch of the unexplained.

Looking forward to what comes next in the series.

Recommended for: fans of Dan Brown, Steve Berry and anyone who enjoys historical mysteries with a supernatural edge.
Final verdict: A compelling, eerie read that proves Cooper still knows how to keep readers hooked.

[Toni Osborne · Rating 4 out of 5]

Cal Donovan Vatican Conspiracy book# 8

I enjoyed this gripping thriller for its intellectual puzzle and its fast-paced conspiracy, as well as a story that includes a mystery, murders and a religious intrigue. Mr. Cooper knows well how to deliver a blend of historical, religious and scientific themes to captivate us from the get-go till we reach the last word.

Although this book is part of a series, it stands well by its own although I highly recommend to have a look at the previous books in order to know more about the protagonist, Cal Donavan, a Harvard professor, and Elisabetta Celestino, a former secretary of State to the Vatican. The two play a pivotal role in this latest. Be advise: IMO, some books are better than others but don’t give up, in the long run you will be rewarded.

The story in a few words:

Three nuns are murdered in the attic of a Boston convent. There are no witnesses. No shell casings.

The only things missing are their rosaries.

Days later, a Boston medium claims her spirit guide has identified the killer: a broken priest with an antique revolver. A single newspaper column turns that claim into a city-wide witch hunt.
Cal Donovan and former Vatican secretary Elisabetta Celestino step into the city’s séance rooms to test the story. What they uncover will reaches generations and the birth of modern spiritualism.

My last words:

The suspense never ends but I had to be all there in order to understand what was going on. We have a cracking police procedural, a medium’s spirit guide, a story about Boston mediums, a brief history of Sir Arthur Conan Doyle and his influence on Boston, a twisted case with roots going back 80 years and it goes on and on. The best a progression in the Cal and Elisabetta saga…awe….love is the air….

Thank you to Book Whisperer and NetGalley for allowing me the opportunity to read this ARC and providing my honest review!

[Faith Flaherty · Rating 5 out of 5]

Since I've been sick all week, I was looking for books to read. I saw Covenant of the Dead by Glenn Cooper on Facebook. The Boston locale, murdered nuns, and it looked like a series. Have I found a new Three Pines Mysteries?

I hope so. I could just picture the locales. Been there, many times. The major characters are Sister Elisabetta Celestino and Cal Donovan. Boston Police Detectives Santos and Trinh, are important, too.

Three nuns are murdered and there was nothing stolen except their rosaries. Eli (Sister Elisabetta) and Cal pay a visit to the nuns. Then in the Boston Globe, there's news that the murderer is a priest with a red nose. That fits the description of only one priest and he's accused. He suspiciously dies before going to trial.

Eli and Cal pay a visit to the medium that said a priest with a red nose did it. There's a picture above the mantel of Arthur Conan Doyle--think Sherlock Holmes. It seems he had been to this very house and had a seance.

That was over a hundred years ago and the Bostonians rioted to have these necromancers out of their city. A riot broke out and the medium's four children burned to death. She blamed the nuns because they were very vocal with their rosaries and singing. Mmmmmm. Keep that in mind.

More tragedy to the medium's family. Her husband and only remaining child were in a car accident. Husband died and the daughter had to have her legs amputated. This is the daughter who earns her living doing seances.

Meanwhile, back in academia (Eli and Cal are professors at Harvard Divinity School). They contact people in the know to look up Arthur Conan Doyle and Boston seance. Their research also uncovers similar nuns' deaths, dating back a hundred years. After putting two and two together, rather parenthetical equations, the answer is revealed.

That's not the end. This is a thriller. Now that you know who and how, you better move fast to stop more murders.

[Paloma · Rating 5 out of 5]

Call Donovan is back and he brings with him a new special friend and a case that will bring back dead nuns from the past!

The Sisters of the Living Well were eight nuns living happily until and intruder killed three nuns in the middle of the night. Sister Kristin, Sister Dora and Sister Lidia were shot using a pillow as a silencer and their rosaries were taken as trophies.

Sister Elisabetta Celestino, Vatican Secretary of State who is coping with the death of her brother Emilio, has left her place as the first female Secretary of State and may be giving up her vows as a nun and Cal is the reason why.

When a local famous psychic makes a claim that her guide mentioned that the killer of the nuns is a red nosed priest, chaos ensues. Father Timothy Bouchard and Father Malloy become prime suspects, as they were close to the nuns. When two elderly nuns are killed with insulin that they didn't need and their rosaries are taken Elisabetta, Detectives Jose and Maria Trinh know they have a serial killer on the loose.

I think this is by far my favorite Cal Donovan book. I enjoyed Elisabetta so much, her work, her achievements and her convictions. Cal Donovan let her do her thing and I liked that about him. The present killings that led to the discovery of the past killings was so intersteresting. The story behind the serial killer was compelling. I felt bad for the priests who were wrongfully accused. I will most definitely go research the feminist catholic women mentioned in the book and their works.
Thank you Netgalley and Book Whisperer for this eARC. All opinions are entirely my own.

[S. Policar · Rating 3 out of 5]

This was an interesting read. Would I read it again? Probably not. While it started off pretty strong, the flame died pretty quickly, leaving a story just barely interesting enough to keep me wanting to know how it ends.

There are a LOT of characters that once their roles are done, are forgotten quickly, even though they were made prominent and front and center before. Once their part is over they're never mentioned again, not even for the main characters to correct what they themselves did wrong.

There isn't a whole lot of growth or development for any of the main characters and I'm wondering how this main character has five more books to make a series when he's one of the most predictable, boring characters I've ever come across in my adventures reading.

The story isn't horrible, it just lacks emotion. There's no feeling to anything that happens except maybe the event that triggers everything else that happens. There was a modicum of emotion in those scenes.

The ending was anticlimactic at best, with no clear outcome to who is the good guy and who isn't. But maybe that was deliberate. Because you do see the point of view from both sides of the case, but at the same time it seemed to glorify and romanticize the crimes that were committed. There's a lot of build up for nothing to have come of it, in my opinion.

This mix of fiction and history in a murder mystery setting is sure to amuse some people, it just didn't for me.

The biggest issue which I'm not sure how it wasn't caught, is toward the end of the book, Mr. Cooper seemed to have forgotten that one of his characters was named Eva and began referring her to as Kay on and off for 25 of the last 50 pages.

[Autumn Danner · Rating 5 out of 5]

This is an even higher octane thriller in the Cal Donovan series! Thank you to Book Whisperer/NetGalley for the DRC of this book. I have read the previous books in the series and was thrilled to see how Cal has personally grown through his past experiences. This book has a little more of a personal slant considering that Elisabetta has left the Vatican and is now working regularly alongside Cal. When three Nuns are murdered, both Cal and Elisabetta become involved tangentially due to their connection to the Church. This story mostly takes place in Boston bouncing from Cal in the present to Arthur Conan Doyle in the past. Cal takes a backseat to the detectives investigating the murder of the Nuns, and their disdain for the help offered by Cal and Elisabetta is evident. But as more information comes to light, the danger to both becomes present. There is less Catholic history and little archaeology in this book, but the church presence is strong and its flaws are not hidden. I found this edition to be very exciting considering the personal aspects for Cal and Elisabetta, and for the search for motive in the murders, for the mystical connection to our lost ones. There is a lot going on over multiple levels, coming together in a race to save the final Nun. This book is another hit out of the park for Cooper!

[Joyce · Rating 4 out of 5]

349 pages

4 stars

A cracking police procedural. The detectives get the call of three dead nuns - murdered in their sleep at a local convent in Boston. The really odd thing is that their rosary beads are missing.

A story in the newspaper states that a medium’s spirit guide says the culprit is a local priest with a red nose.

It takes very little time for the police to hone in on the priest. Is he really the killer? When he is found dead in his room, the case gets closed. But there are doubts.

The medium connections takes the story in an interesting and exciting way to a discussion of the history of a family of Boston mediums, and surprisingly, a brief history of Sir Arthur Conan Doyle. He was a true believer of spiritualism. The book discusses the influence he had on the Boston family of mediums.

This is a real page turner. The twists and turns in the story are many, and interesting. I really liked this book and will recommend it.

The characters are well fleshed out. The writing is exceptional. The tension builds at a continuing pace.

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

[Jodi · Rating 4 out of 5]

This is the first book by Glenn Cooper that I’ve read. It’s not my usual genre, so there were times that I felt it was a slow burn, but it kept my interest and kept me coming back to it whenever I had a spare minute to read. I did get it as an ARC from Book Whisperer and I thank them for the opportunity to read it. I really enjoyed the character development, but felt as though there must’ve been a previous book that as the two main characters felt as though they had history that may have been introduced earlier. That didn’t take away from the enjoyment of the book. There was mystery and build up, as well as the slow burn of the two main characters relationship. She was a nun in the midst of deciding if she wanted to continue as a nun or move in a different, but no less influential position. I really enjoyed the story as it wasn’t what I expected and didn’t end the way I thought it would either. The introduction of Arthur Conan Doyle as part of the plot really added another dimension to the story as well. It’s a murder mystery with a plot that you will never expect. I greatly enjoyed it.

[Don Weymouth · Rating 5 out of 5]

Thanks to Netgalley and Book Whisperer for the pre-release copy of the book to review.

Glenn Cooper is doing well with his character Cal Donovan, a professor at Harvard's School of Divinity with close ties to the Vatican. I highly recommend that the reader starts with the earlier Cal Donovan novels in order to understand his relationship with the former Secretary of State for the Vatican, Elisabetta Celestino (Eli.) Cal promises Eli that he will give up his destructive drinking and helped her secure a position at Harvard to also be a professor. She is the hit of Harvard, everyone wants to be in her classes.

Three nuns are murdered and a medium is quoted in the newspaper as identifying the killer. She convinces Cal to go with her to a seance, and she then hears something about her brother in this sitting which, as it turns out, was true. Being a nun, she is very skeptical of mediums and then researches that Arthur Conan Doyle was almost addicted to going to mediums and foreseers.

The author goes back into history as is his trademark and brings about a great story of intrigue, the crossing of religion and mysticism and they solve a mystery of the past as well as the present. I won't give away anything that will give foreshadowing to the author's surprises. I really couldn't put this book down!

[Beth · Rating 4 out of 5]

I know when I begin a Glenn Cooper novel, I will be drawn in by the non stop action from the first chapter forward. Covenant of the Dead is no exception. One of the most intriguing aspects of Cooper’s writing is way of storytelling through developing historical events that connect to the present day mystery. The story opens up with three nuns shot dead in their beds while they sleep. The detectives are at a loss except for a few clues, a medium whose family has had the gift of speaking with the parted for over a hundred years, and Cal Donovan the Harvard Professor who can put the puzzle together. Like I have said before, I will read any mystery that Glenn Cooper writes because I am sure to be entertained and taken on a twisty ride.

Thank you, NetGalley, Book Whisperer and Glenn Cooper for providing me with an advanced reader copy to review.

[Justyna · Rating 3 out of 5]

The first third of this book had me hooked — intriguing, fast‑paced, and full of promise. But after that strong start, the story lost some of its spark for me. There were a lot of characters and plot threads, and instead of building momentum, it started to feel a bit scattered. By the time I reached the conclusion, it was… fine. Some exciting moments, some good reveals, but overall a bit forgettable.
Cal has definitely mellowed since the previous book. I can appreciate the character growth, but I have to admit I missed the rough, messy edge that made him so compelling before. On the bright side, I really enjoyed watching his relationship with Elisabetta develop — she’s a great addition and brought a dynamic I liked.
In the end, it was an okay read with a solid premise, but I don't think it’ll stick with me.

Thank you NetGalley and Lascaux Media for the arc.

[Trisha · Rating 5 out of 5]

This certainly was a different book then my normal. It was filled with nuns, priests, a pope, a scholar, and a medium to round out the cast, and one is a murderer, and has been for a long time, but who? This book will take you all around the Boston area and some areas in Vatican City. But when a nun and the scholar, being old friends, team up for a paper to publish on the subject of nunicide they didn’t know they would also be the ones to solve these heinous crimes.
Kind of Dan Brown but not either. It was a wonderful book and I loved the characters, even the creepy ones. This book will keep you guessing until the end but learning some of the insights in to the Catholic church is interesting, especially the past. I really like this book because of the mystery that is hard to solve.
Review copy provided by Netgalley

[Susanne · Rating 5 out of 5]

A great mystery. Elisabetta, formerly of the Vatican, has moved to Boston with Cal and become a professor at Harvard. Cal is still hoping to pursue a relationship with her that's more than just a close friendship but is happy to wait for the right time. Three nuns are killed in their sleep and the case has the police puzzled. Cal and Elisabetta become involved in the case on the sidelines after taking an interest in the case. The mystery deepens after two more nuns die. A very twisty case with its roots going back 80 years. Fascinating and intriguing, I really enjoyed this story and it was good to see Cal and Elisabetta working together again.
Thanks to Netgalley, Book Whisperer, and Glenn Cooper for the free ARC. All opinions are my own.

[Sarah · Rating 4 out of 5]

This is the third Cal Donovan thriller I've read, and it didn't disappoint! Cal has persuaded Sister Elisabetta Celestino, former Vatican Secretary of State, to move to Boston to teach at the university...and maybe be his girlfriend one day! Three nuns are shot dead, closely followed by another two being poisoned, and the mystery deepens when a local medium points fingers at a red-nosed priest. It turns out there was a similar case 40-odd years ago and Cal and Eli set to solving the mystery.

This wasn't my favourite Cal Donovan thriller (I went to a Catholic school and have a soft spot for nuns!) but still an excellent read, and has firmly cemented Glenn Cooper as a must read author for me!

[Claudete Takahashi · Rating 5 out of 5]

Cal has convinced Elisabetta to accept an offer to become a professor at the Harvard Divinity School. He's madly in love with her but she is still pondering whether or not she wants to leave her vows as a nun. After 5 nuns are murdered in the Boston area, they started to search for similar crimes and discover that years past another 5 nuns had been killed and the crimes were never solved. Everything seems to be linked to a family with women with the power of communicating with the dead. This story is particularly interesting as it explains the beginning of the spread of the Spiritism throughout the world and how it clashed (and stilll does) with the Catholic Church. Another great addition to the series.
I thank the author, his publisher, and NetGalley for this ARC.

[Tina G · Rating 4 out of 5]

When I picked up Covenant of the Dead, I didn't realize it was book 6 in the Cal Donovan Vatican Conspiracy thriller series, but that's ok! At no point did I feel like I was missing something from previous installments pivotal to the plot.

Murdered nuns, suspicious church officials, spiritualists/mediums, and ties to Sir Arthur Conan Doyle weaves a plot full of twists. Keeps you guessing!

Great read! I have now added more of Glenn Cooper's books to my growing TBR list!

Thank you to Book Whisperer and NetGalley for allowing me the opportunity to read this eARC and providing my honest review!

[Reeca Elliott · Rating 4 out of 5]

Three nuns are murdered in the attic of a Boston convent.
There are no witnesses.
No shell casings.
The only things missing are their rosaries.

I love a tale that keeps you guessing…and then some. I enjoyed the dip into mysticism and seances. Add in the biblical references and…this will come as a surprise…Arthur Conan Doyle and you have a good read.

And that is just part of this story. Don’t forget about the murders and the innocent man that has been arrested. This is a wild ride indeed!

Need a tale that explores all options…THIS IS IT! Grab your copy today.

I received this novel from the publisher for a honest review.

[Doug Yonce · Rating 5 out of 5]

A professor, a nun, Sherlock Holmes’s creator a two police detectives go to a séance — sounds like a joke is coming. But what we get is an excellent addition to the Cal Donovan series. We get to visit the past and present as murdered nuns seem to know have connection to previous deaths. Cal and Eli(sabetta) ‘s relationship grows stronger and they put their formidable skills to work as the aid the detectives. I received an advance copy of this book from NetGalley and the publisher and voluntarily provided an honest review.

[Andrea A · Rating 5 out of 5]

My thanks to Net Galley, Lascaux and the invitation I received from Book Whisperer to review this arc.

Another winner from this author! I absolutely loved it. The story pulled me in right away ! 3 nuns shot in an attic while they slept and their rosaries taken. Cal and Elizabeth are back to assist the police in their investigation . Then a paralyzed medium has information on the case no one else knows. I loved how a similar past case they discovered ties into the present. Throw Sir Arthur Conan Doyle in and you have a great read.

[Anonymouse · Rating 2 out of 5]

I have read a few of these Cal Donovan books now and I won't try any more. In the broad sense these are Dan Brown books with some supernatural thrown in. That's OK, but they are also mysteries and it's the mysteries that I can't take. This one is the worst but I can't tell you the problem without giving away the plot. Grrr. So ok. If you already like Cal Donovan and his world, then you will probably like this book. If you are new to the series or if you already have doubts about the previous books, don't bother with this one.

I received a review eARC of this book through NetGalley.com.

[Charisa Flaherty · Rating 2 out of 5]

Thank you to NetGalley for the opportunity to read this book. I have enjoyed the Cal Donovan books I have read up to this point and was excited about this one. However I feel it was all over the place. There were a lot of things going on and while they did tie together in the end it took a lot to get there. All the flashbacks were excessive and, to me, not necessary. They detracted from the action of the main story. Also I felt the premise of blaming the priests and nuns for the family tragedy was a bit of a stretch. I would still read more Cal Donovan books and hope this one was an anomoly.

[Terry M · Rating 5 out of 5]

Murdered nuns, seances, deception and unexpected twists. Cal and Eli become involved in assisting the police with the recent murders, but uncover so much more. I like the way history is entwined with the present and we get to see a more vulnerable side to Cal as his relationship with Eli evolves. Highly recommended. I received an ARC from Book Whisperer/Netgalley and I am leaving this review voluntarily.

[Destiny Imperati · Rating 5 out of 5]

ARC Review ✨️

♡Mysterious, suspenseful and incredible♡

Thrillers are one of my top genres and always have been! I love when a thriller is instantly able to grab my attention and keep me on the edge of my seat. That's exactly what this book did!

From the characters to the suspense, it all blended perfectly! At times the story got so intense, I felt like I couldn't get to the next part fast enough!

Tropes:
🖤Thriller/mystery
🖤Historical
🖤Religious
🖤Standalone

Huge thanks to the author and The Book Whisperer for the early review copy!

[Jodi Bennett · Rating 5 out of 5]

5 nuns are killed in Boston. Elisabetta drags Cal along to investigate as she smells something wrong about the whole investigation. This investigation involves mediums and seances. This was a fascinating story and you really care about all the characters. I really like how the love story takes a back seat and doesn't overtake the storyline. This is a well written story and moves quickly. Glenn Cooper gets it right again!

[Darlene Golbitz · Rating 4 out of 5]

Courtesy of The Book Whisperer and Netgalley, I received the ARC of Covenant of the Dead by Glenn Cooper, another thriller in the Cal Donovan series. This Boston based mystery has historical elements of Spiritualism, séances, and revenge, along with thoughtful comments on the trajectory of the Catholic Church. With familiar and engaging characters and a twist at the end, I couldn't stop reading!

[Beverly · Rating 3 out of 5]

TY to netgalley for digital arc...
A good enough read. Religious drama, who dunnit...however LOTS of characters, lots of back and forth time frames to the point that things became almost too convoluted to follow. And, of course, the inevitable love connection. It was, good enough.

[Lynn Hill · Rating 5 out of 5]

What a great book! I really enjoyed reading this. It was definitely a page turner that kept me up all night! I think you will like it too! Thanks for the great book!

[Anita Coates · Rating 4 out of 5]

murder mystery with a paranormal twist. keeps you guessing until the end. I really enjoyed the story

[Monique Corbeil · Rating 5 out of 5]

One of the best book by Glenn Cooper. A real page turner