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Mac MacKenna is a man in transition.

After an exciting 20-year career in the U.S. Air Force Special Operations unit known as Pararescue, Mac retired and returned to his hometown of Brookfield to live near his only family, his sister, Maggie, and her two young daughters. Mac never married. He has no children. And now, he has no job.

Mac’s sister, Maggie Donaldson, lost her husband, Bobby, two years ago—a sheriff deputy killed in the line of duty. Maggie’s an emergency room nurse who juggles trauma and being a single parent. She’s lonely and tired, but happy her brother’s finally home.

Randall Jackson and his wife, Susan, have a good life. Their son attends Blackstone Academy, a public school subsidized by the affluent parents in the community who want to keep the school exclusive for their children. Randall’s loan business is successful. They regularly socialize with the mayor and police chief. But money can’t buy happiness. Behind the doors at the Jackson mansion, life is anything but happy.

Mac’s restless and unsure of how to be a civilian when he receives a phone call. The police chief wants Mac to pose as a school marshal at Blackstone Academy.

His mission: Identify and eradicate the criminal activity at the school before children die.

Soon enough, his former life of loaded weapons and death-defying rescues has been replaced by arrogant parents, self-serving politicians, and questionable employees.

Unfortunately for Mac, meddling with the rich can have deadly consequences.

A Mystery/Thriller based on disturbing reality.

240 pages, Kindle Edition

Published December 22, 2016

32 people are currently reading
41 people want to read

About the author

Robin Lyons

5 books16 followers
I write small-town murder mystery novels. Escape reality grab one of my books, your favorite drink, and relax.

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Displaying 1 - 11 of 11 reviews
Profile Image for Katy The Sleepy Reader.
393 reviews40 followers
January 24, 2022
I received this book last year after winning a giveaway. The author sent me a signed copy. It went in to my TBR pile and I have to admit, I'm sorry it took me so long to get to it because it is a fantastic read!

Cole 'Mac' MacKenna is the kind of guy you want to root for. Retired from the U.S. Air Force, he was once part of pararescue team in an elite special ops group. After 20 years, he's retired when a cop friend asks him to pose as a school marshal to flesh out who might be dealing drugs to the students. The mayor's son has already overdosed once, and he wants heads to roll.

He starts by making a list of the students and faculty and then goes about trying to eliminate each subject. The head of the school does not like Mac and is out to get him from day one. Throw in an arrogant, abusive parent of one of the students and a family with a huge secret and you have one heck of a great story.

I'll say one thing, the author definitely knows how to create characters you love to hate. I found myself frustrated with several of the characters and was really hoping something would happen to them, lol. The atmosphere is well written, and I really like Mac's dog, Roxy. I've always had a soft spot for animals.

One thing that bothered me was Coaches mom. I really disliked her and was very disturbed to see her be very lackadaisical about the disappearance of her son. As a mom, I couldn't imagine acting the way she did and I'm hoping we get some answers on this topic.

Overall, I really enjoyed this story. The chapters are short, which I like, and it's a part of a series which I am very much looking forward to reading. There is a prequel about Mac himself I intend to check out next. I would highly recommend this book if you are a fan of the mystery genre. I received this book free from the author for an honest review.
Profile Image for Marie Sembar.
104 reviews14 followers
February 9, 2021
The main character Mac has the best quality! He's willing to lose his job to do his job and I never stopped rooting for him. After becoming a school marshal to identify a drug source, Mac systematically eliminates or flags students and teachers as potential dealers. Every character had some small flaw--as humans do--but none were an obvious choice so I was either always changing my guess or outright stumped!
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I absolutely loved that the story was not just about finding a drug dealer. Within any school or community there are egos to deal with and Mac doesn't back down or hesitate to become involved in one family's shocking secrets!
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If I could make one request for future School Marshal novels it would be to include additional flashback scenes from Mac's time in the Air Force! That glimpse into his former career helped me understand a bit of his psyche! As an early chapter my heart was racing!
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Unknown Threat was a really enjoyable read. I did not expect, but loved, all the twists that filled the story! Bonus: The chapters were short!
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I would highly recommend this to anyone who reads mystery, thriller, crime/detective novels, and even true crime readers.
Profile Image for Nannette Kreitzman.
Author 46 books54 followers
July 9, 2022
Enjoyed this!

Lyons has created an interesting ensemble of flawed characters in her novel, Unknown Threat. Retired Air Force special ops sergeant, Mac MacKenna, has agreed to help his police officer friend determine who is selling drugs at Brookfield Academy. Posing as a school marshal, Mac lifts the lid on that and so much more. After unraveling a series of interwoven crimes, he’s left wondering if the right people have answered for them.
Profile Image for Sarah Hill.
Author 7 books59 followers
November 10, 2020
This is a fun and easy crime story that had whispers of Janet Evanovich's Stephanie Plum series. Like the Plum series, this story is a light crime mystery that keeps you guessing. I love the relationship between Mac and Roxy, his German Shepard and an't wait to follow Mac into his next adventure to learn more about him and see what other cases he gets himself involved in.
Profile Image for Sandra.
Author 15 books575 followers
February 4, 2022
Mac MacKenna, recently retired from Air Force Special Operations Command, has a new job as a school marshal. He monitors kids from kindergarten through twelfth grade—a task completely out of his comfort zone—in an undercover search for crime.

The author builds reader anticipation, layer by layer, as lies, deceit, and threats sprinkle Mac’s interactions with staff, students, and parents. Carefully developed characters and their back stories heighten the suspense throughout, creating doubts about who is guilty and who isn’t.

I loved Mac’s character: strong, honest, and protective of family and friends. That his faithful German Shepherd, Roxy, displays similar qualities is no surprise.

Short chapters sped up my reading pace, and I kept flipping the pages to get to the end. An exciting first book in a series!
Profile Image for Dr. Leanna Floyd.
62 reviews14 followers
April 16, 2021
Unknown Threat is a suspenseful book filled with mystery that revolves around Mac, a decorated veteran, who goes undercover as a school marshall to figure out who is involved in selling drugs to the students at the school. Mac is faced with different challenges as he navigates working in a school setting and dealing with parents and staff members who are not thrilled by his presence at the school. Mac’s skills are put to the test when people end up dead in a town that’s filled with secrets, and he has to face the reality that even the ones closest to him are not who they seem as he continues to unravel the web of lies surrounding him. The author did a great job creating depth to Mac’s character giving readers a comprehensive understanding of his personality and motives that make him tick.

Overall, the author did a great job creating a captivating and thrilling read that has readers anxiously waiting to see what will happen next. Readers will enjoy trying to figure out the clues in this story as they put together the pieces making this an engaging and entertaining read. This is a great book for mystery lovers looking to get carried away in a story filled with twists that will keep them guessing until the end.
Profile Image for Deborah Taylor-French.
Author 1 book105 followers
September 30, 2022
I enjoyed this crime story because of the interesting mix of characters, also because the tension and main character, Mac McKenna, drove the story forward. Mac takes a job as a school marshal as a favor to a friend. I liked how Mac admitted to not having had much experience with children, besides his two nieces who live nearby. His sister and his nieces adore him, and he brings his lovely dog to play with them when he visits.

Author, Robin Lyons, knows children and grammar schools well and uses it in the daily demands made on teachers and students. Also, parents play roles in the daily activities and disagreements between themselves and the school staff. The author waves is sub text and the plot skillfully end times magically, to both surprise readers plus make us yearn for more information.

Ferreting out the guilty party in supplying illegal party drugs to the students turns out to be something Mac can do well. He works in a calm and organized fashion ticking off his list of suspects. Meanwhile, one of the student’s dad’s is granted a restraining order from “Mac.” There are other skillfully twists and turns, but I will let you feel the surprise.
Profile Image for Darcia Helle.
Author 30 books736 followers
September 30, 2019
Reading Unknown Threat reminded me why I'd never want to go back to high school!

Despite my high school aversion, this is a quick, fun read. The plot is pertinent to today's issues, but doesn't weigh us down in misery.

I love Mac's character! So many fictional heroes these days are the 'broken bad boys', who are either alcoholics or addicts, barely functioning while fighting some sort of personal demon. While Mac does have his personal demons (Don't we all?), he isn't wallowing in his issues and he's not battling - or reveling in - addiction. He's tough and definitely has the bit of bad boy going for him, but he's also the kind of man you'd want protecting your child.

I really enjoyed this first book in the School Marshal Series. I'm looking forward to spending more time with Mac!
Author 1 book69 followers
July 10, 2017
‘Mac’ MacKenna, ex-Air Force Special Operations, takes a job at a prestigious public school serving the rich. Mac is a School Marshal, assigned to find a drug source.

Mac has no idea how to work with kids and now finds himself surrounded by snobbish rich juveniles. And. He’s not liked by the Principal who has her own hidden presumptions. Needless to say, Mac’s job is difficult, but not for this ex-military man.

Except for the use bad language, I liked this story. Although I don’t think I’d like Mac for a next door neighbor, I wouldn’t mind him watching over my children.

Mystery and suspense filled the pages as I tried to figure out the “who did it” of the story. (I never did.) Twists made this an exciting read.
Profile Image for Angela Gascoigne.
Author 10 books154 followers
June 4, 2017
When Mac, retired from the U.S. Air Force, is offered an opportunity to make a difference in his community he’s reluctant at first but later throws himself into the challenge. He soon finds himself embroiled in a whole lot of trouble and wonders if he’s made a huge mistake. But, with his loyal companion, Roxy by his side and the support of family and friends maybe he can crack the code and solve the puzzle unfolding in front of him.

This crime mystery kept me guessing right until the end!
Displaying 1 - 11 of 11 reviews

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