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ONE IS THE DEADLIEST NUMBER: A Purrs and Personality Types Mystery
A cat cafe in a small desert town +
A class on the Nine Personality Types +
Locals brimming with secrets =
Cozy mystery purr-fection
Book one in a brand-new series!
67-year-old Constance Kincaid and her mischievous rescue cat, Mr. Cinnamon, are the newest residents of Cherry Hill, California, a quaint, relaxing tourism destination hit by hard times. The only business staying afloat is CHATeau Savannah, the cat café whose featured resident is, you guessed it, a wild-looking but super-sweet Savannah (a serval mixed with a domestic).
Eager to carve out a place in the community, Constance teaches a class on her favorite the Nine Personality Types. To engage her bickering students—and keep the class from being canceled—Constance likens them to amateur sleuths, unlocking the secrets of human nature to solve mysteries.
It was only supposed to be a fun thought experiment.
But when the once-beloved Cherry Hill tourism trolley explodes, killing its driver, Constance and her students must put their knowledge to the test and catch a fur-midable foe... Because not only was Constance the last person to ride the trolley before the accident, she may have been the real target!
This laugh-out-loud, ensemble mystery with heart is ideal for fans of Miss Marple, The Thursday Murder Club, and Only Murders in the Building.
Purrs & Personality Come for the cats. Stay for the crime.
A class on the Nine Personality Types +
Locals brimming with secrets =
Cozy mystery purr-fection
Book one in a brand-new series!
67-year-old Constance Kincaid and her mischievous rescue cat, Mr. Cinnamon, are the newest residents of Cherry Hill, California, a quaint, relaxing tourism destination hit by hard times. The only business staying afloat is CHATeau Savannah, the cat café whose featured resident is, you guessed it, a wild-looking but super-sweet Savannah (a serval mixed with a domestic).
Eager to carve out a place in the community, Constance teaches a class on her favorite the Nine Personality Types. To engage her bickering students—and keep the class from being canceled—Constance likens them to amateur sleuths, unlocking the secrets of human nature to solve mysteries.
It was only supposed to be a fun thought experiment.
But when the once-beloved Cherry Hill tourism trolley explodes, killing its driver, Constance and her students must put their knowledge to the test and catch a fur-midable foe... Because not only was Constance the last person to ride the trolley before the accident, she may have been the real target!
This laugh-out-loud, ensemble mystery with heart is ideal for fans of Miss Marple, The Thursday Murder Club, and Only Murders in the Building.
Purrs & Personality Come for the cats. Stay for the crime.
308 pages, Kindle Edition
Published September 23, 2025
1 person is currently reading
18 people want to read
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Displaying 1 - 8 of 8 reviews
November 20, 2025
What a fun read! This fresh take on the cozy mystery has such a great voice; it's quirky in the best possible way and had me smiling from page one. The Enneagram angle is really interesting, and you don't have to know anything about it going in. (I didn't! But it was fun to learn.) The characters and small-town drama made it particularly enjoyable, and the plot kept me guessing the whole time. If you're looking for a cozy that offers something a little different, this one's definitely worth picking up.
October 20, 2025
A cat café, cozy mystery, and quirky characters. What is there not to love here? One Is the Deadliest Number by Hadley Hartwell is the first in the Purrs and Personality Type series. It was such a fun read and had a different premise to other books - enneagram (the concept of nine personality types).
Constance Kincaid discovers her husband’s infidelity upon his death and swaps the East Coast for the West Coast, choosing Cherry Hill, California, and buys the Upside-Down House on a whim. She finds out the house is considered a historical place of interest for the town and needs to allow tours of the house and by not doing this, it is a strike against her with the community.
After six months of solitude, she decides to teach free classes on enneagram at the local library in order to meet people. Her class is comprised of individuals who are eclectic, leading very different lives from each other, yet they form a bond and friendship as they investigate the crash of the much-hated city trolley and the death of Isaac. They use their newfound knowledge of enneagram to clear a fellow student’s husband of suspicion of the crimes.
One of the highlights of this book is the CHATeau Savannah, a Parisian themed cat café, with the star of the café, Savannah, and her owner, Crystal Bae. You know Crystal and Wesley will get together at some point, but the conflict they have at the beginning is entertaining.
I can’t say enough good things about the characters in this book and how much fun they are. Chase calling Constance’s cat “Sassy Pants” instead of Mr. Cinnamon is an example of the humor in this book. Chase is so full of life, and his personality is a delight. The individuality of each member of the group adds to the story, and I can’t wait to read about their future adventures. Here’s hoping there are more stories in this series!
Constance Kincaid discovers her husband’s infidelity upon his death and swaps the East Coast for the West Coast, choosing Cherry Hill, California, and buys the Upside-Down House on a whim. She finds out the house is considered a historical place of interest for the town and needs to allow tours of the house and by not doing this, it is a strike against her with the community.
After six months of solitude, she decides to teach free classes on enneagram at the local library in order to meet people. Her class is comprised of individuals who are eclectic, leading very different lives from each other, yet they form a bond and friendship as they investigate the crash of the much-hated city trolley and the death of Isaac. They use their newfound knowledge of enneagram to clear a fellow student’s husband of suspicion of the crimes.
One of the highlights of this book is the CHATeau Savannah, a Parisian themed cat café, with the star of the café, Savannah, and her owner, Crystal Bae. You know Crystal and Wesley will get together at some point, but the conflict they have at the beginning is entertaining.
I can’t say enough good things about the characters in this book and how much fun they are. Chase calling Constance’s cat “Sassy Pants” instead of Mr. Cinnamon is an example of the humor in this book. Chase is so full of life, and his personality is a delight. The individuality of each member of the group adds to the story, and I can’t wait to read about their future adventures. Here’s hoping there are more stories in this series!
September 27, 2025
When 67 year old Constance Kincaid is widowed she moves to Cherry Hill on a whim, leaving her old life behind and bringing nothing with her but her recently adopted cat Mr. Cinnamon, her love for Agatha Christie’s Miss Marple and her firm belief in the usefulness of Enneagram analysis. She is hoping for a warm, cheerful place to recoup, but Cherry Hill is a small town with small businesses struggling to stay afloat, and not everyone in town are eager to welcome her with open arms.
Determined to make herself a part of the community, Constance decides to offer free Enneagram classes at the local library. She is hoping to inspire her students to get to know themselves better, but when the local trolley driver who had many enemies among the Cherry Hill business owners is killed, Constance and her students embark on a quest to use their knowledge of Enneagram personality types to find the murderer.
One is the Deadliest Number is a cozy mystery with a really interesting twist. Where Agatha Christie’s Miss Marple uses her knowledge of human nature to solve crimes, Constance and her students use Enneagram analysis to understand human behaviour and catch a killer, and learn about themselves and each other in the process.
An engaging, comforting and quirky mystery with a lovable cast of flawed but sympathetic characters, and a story filled with interesting and fun descriptions of cats and Enneagram analysis in action. Recommended for all cozy mystery fans and especially for cat lovers who will no doubt fall head over heels for the fun and charming descriptions of Mr. Cinnamon’s antics and the joy and meaning he brings to Constance’s life.
Determined to make herself a part of the community, Constance decides to offer free Enneagram classes at the local library. She is hoping to inspire her students to get to know themselves better, but when the local trolley driver who had many enemies among the Cherry Hill business owners is killed, Constance and her students embark on a quest to use their knowledge of Enneagram personality types to find the murderer.
One is the Deadliest Number is a cozy mystery with a really interesting twist. Where Agatha Christie’s Miss Marple uses her knowledge of human nature to solve crimes, Constance and her students use Enneagram analysis to understand human behaviour and catch a killer, and learn about themselves and each other in the process.
An engaging, comforting and quirky mystery with a lovable cast of flawed but sympathetic characters, and a story filled with interesting and fun descriptions of cats and Enneagram analysis in action. Recommended for all cozy mystery fans and especially for cat lovers who will no doubt fall head over heels for the fun and charming descriptions of Mr. Cinnamon’s antics and the joy and meaning he brings to Constance’s life.
November 26, 2025
For anyone who likes to read cozy mysteries, “One Is The Deadliest Number: A Purrs and Personality Types Mystery” by Hadley Hartwell is a great choice. I was fortunate to come upon this book at a local community fair where I was able to meet the author. Turns out she’s a great story teller.
The story is unique, well laid out, and kept my interest throughout the entire story. Hartwell’s use of multiple character POV in telling the story brings the reader deeper into the minds of the characters of this small, quirky town near Palm Springs. Her use of the Enneagrams (a system of identifying and classifying personality types into 9 unique types) added an interesting twist to the method of solving the murder of the town’s trolley driver. In the end, while there was a town’s worth of suspects, it took an outsider to bring the killer into focus. If you like Agatha Christie or “Murder She Wrote”, you’ll like this book.
I look forward to reading book two in the author’s series, “It Takes Two To Murder.”
The story is unique, well laid out, and kept my interest throughout the entire story. Hartwell’s use of multiple character POV in telling the story brings the reader deeper into the minds of the characters of this small, quirky town near Palm Springs. Her use of the Enneagrams (a system of identifying and classifying personality types into 9 unique types) added an interesting twist to the method of solving the murder of the town’s trolley driver. In the end, while there was a town’s worth of suspects, it took an outsider to bring the killer into focus. If you like Agatha Christie or “Murder She Wrote”, you’ll like this book.
I look forward to reading book two in the author’s series, “It Takes Two To Murder.”
September 11, 2025
What a delight! Small town cozy meets the zip of crime drama. Constance, the retiree and sleuth is a kick. Hadley Hartwell's weaving in of the nine personality types to solve the mystery is brilliant. And Mr. Cinnamon the cat is a lovey for the ages. Love the "Only Murders in the Building" and "Murder She Wrote" vibes. I can't wait to return to Cherry Hill for more of this wildly entertaining series.
October 16, 2025
Constance was definitely a different type main character than I was used to in a cozy mystery, but she grew on me along with her sweet cat, Mr. Cinnamon. At first I wasn’t crazy about some of the people in the class she decided to teach, but they each had traits that sorta grew on me as well. The showdown outing a killer was a good one as was the very ending with everyone gathered together. I’d be interested in reading the next book.
September 9, 2025
If I could give 4.5 stars, I would! What a well-written cozy mystery, full of interesting characters and unexpected plot twists! The heroine Contance Kincaid is prickly yet empathetic, with a surprising amount of depth. Especially unique is Hartwell’s thematic use of the Enneagram concept throughout the novel. You won’t find another book like it out there!
November 12, 2025
This is such a fun cozy mystery, my first foray into the genre! Being a fan of cat cafes, this book already has a lot to offer me. The colorful cast of characters are a wild diversion, and I'm looking forward to seeing what they get up to next time. I felt reconnected to my old Encyclopedia Brown books that I enjoyed as a child, but Constance is more my speed now. A very delightful read.
Displaying 1 - 8 of 8 reviews