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Rollback

Rollback

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Mike Mansfield is a unique individual. Burly and in his mid-fifties, Mansfield’s view of justice is what some might call chaotically good. To him, justice does not involve putting child traffickers in prison to enjoy three squares a day and television privileges. Mansfield has a better solution, one far more appropriate and direct. Every trafficker he finds is handed over to the father of the victims, where the families themselves decide what level of justice is appropriate.

Now, after working quietly in the shadows for years, Mansfield is finally discovered by David Bruni, a tech billionaire with aspirations of putting his money to better use by creating a new technology never before attempted. A powerful computer system called PICSS, capable of ‘stitching’ together billions of daily photographs taken around the globe and uploaded to the cloud. A very real technology capable of creating a snapshot of anywhere in the world in near real-time. But what Bruni demonstrates to Mansfield is the astounding ability to “roll back” those images, in effect creating a digital time machine, reaching back days to weeks and even years.

The system is utterly astonishing and, to Mansfield’s surprise, purposeful. Bruni built the system in a desperate bid to find his own missing daughter. Bruni has also been tracking Mansfield with his new PICSS system and now wants to know why Mansfield has been so effective at finding children. And what precisely does Mansfield appear to be doing with the traffickers he captures?

Mansfield takes the job and sets out in an attempt to find out what happened to Bruni’s daughter. In doing so, he connects with Leslie Salazar, the INTERPOL agent who initially worked the April Bruni case.

For his part, Mansfield trusts no one save for a select number of confidants who quietly assist behind the scenes. People who are ‘invisible’ in perhaps the most surprising way possible.

Once on the ground at the site of the girl’s disappearance, Mansfield, along with the help of Bruni’s PICSS system, begins uncovering details never before known to Bruni nor the police. Details that suggest the disappearance of Bruni’s daughter may not be at all what was previously believed.

Bruni is about to find that he has hired precisely the right person. Mansfield is no stranger to the harsh world of abductions and trafficking. Nor does he have any qualms about hurting those who harm others. Mansfield is ruthless, and Mansfield is unforgiving, and justice is coming.

349 pages, Hardcover

Published July 15, 2025

1816 people are currently reading
3602 people want to read

About the author

Michael C. Grumley

18 books1,315 followers
Michael C. Grumley is the author of the best-selling BREAKTHROUGH series with over two million books sold. He lives in Northern California with his two young daughters. He’s an avid reader, runner and most of all father, and dotes on his girls every chance he gets. He loves hearing from readers while he works on the next ROLLBACK book.

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5 stars
856 (61%)
4 stars
410 (29%)
3 stars
98 (7%)
2 stars
22 (1%)
1 star
7 (<1%)
Displaying 1 - 30 of 103 reviews
1 review
July 26, 2025
Wow, as usual, Mr. Grumley brings it all to the read! I love how he has incorporated "the invisibles" into his writing - such an unseen asset by most of the world!
This had me on the edge of my seat, reading far too fast as I could not put it down, then relieved at the end to know there will be more to come from these characters :) Bring it on! 🙏
5 reviews
August 10, 2025
Talk about resonating in today's world...

This reads as smooth as his Breakthrough series, which you need to read if this is your first experience reading Michael Grumley, and just as mind-bending. He's so good at writing things calmly, while still taking you on a heart-stopping read that you can't put down. The intelligence level at which he writes clues you in on his ability to harness his own knowledge and keep you believing in what's possible in this world!
Profile Image for Kristine.
3,431 reviews52 followers
December 20, 2025
This book was such an unbelievably pleasant surprise!

I'm not even sure why this surprises me because so far, everything that I have read by Mr. Grumley has been a joyous success. This book though, takes his expertise at character development, then adds in a crazy, interesting mystery and then to top things off.....ramps up the tension and action level to the point that I found myself holding my breath at certain parts.

DEFINITE WINNER!!!

This series introduces us to MMC Mike Mansfield. He is a successful investigator who finds lost people - manly children. He has seen the worst that the world can do, and he is still adamant in trying to do his part to save that one person. He is also a vigilante. Yes, he finds the missing. But, if he can also catch the perpetrators, he gives the decision on their punishment to the fathers of the victims. To make the choice on how to handle the punishment of the men that hurt their daughters. Emotional? You better believe it.

Mansfield also uses a fantastic team that he calls the "invisibles". These are older individuals who have been successful at their vocations in their lifetime. But now that they are senior citizens, the world tends to not see them anymore. So....if they are invisible, he decides to utilize their expertise and experience to his advantage. It is an awesome success.

This case takes us on a journey as we follow Mansfield as he takes on a 4 year old case of the missing daughter of a billionaire tech mogul. It does not take long for him to realize that things are not what they seem, and the original investigations went in the complete wrong direction.

This is only the first book in this series and their is going to be another book out in the next month or so.

I can't wait.

22 reviews
July 26, 2025
C.E.W.

Really enjoyed this book. Not what I was expecting. The characters were amazing and relatable. I'm one of the invisible people out there, so nice to know we have our own super power. Great read Michael C. Grumley, so looking forward to book #2 and beyond.

10 reviews
July 26, 2025
New Concept

Love the concept, the characters, the possibility for new adventures. Really great job. Looking forward to the next Mansfield retribution, intriguing tech, and story.

3 reviews
July 25, 2025
great book

You have no idea where this book is going at the start, which makes the story even more interesting. Great book and great writer. All of his books are well worth reading.
Profile Image for Michael.
573 reviews8 followers
July 24, 2025
Great mix of technology and thrill.

Grumley does not disappoint! This story pits interesting technology against the dark underbelly of society. The technology is artificial intelligence. The underbelly is human trafficking. Buckle up for quite a ride!
Profile Image for Michael Scott Scott.
Author 1 book4 followers
July 21, 2025
Rollback is fantastic!

Author Michael C. Grumley has another winner adventure thriller story on his hands! Great characters, fast-moving action; I gobbled up Rollback and am hungry for more. Type faster Michael!
45 reviews4 followers
July 18, 2025
Very intriguing

This was a bit darker story than I’m used to, but good at gently describing a horrific problem growing in our society. Trafficking! Probably something we should all be paying more attention to. It’s hard, but necessary if we are going to effect a solution. Read it! Put yourself in those shoes! Strongly recommend.
3 reviews
Read
July 20, 2025
HIGHLY RECOMMEND- Great Read!

This book was fast-paced from the jump. It kept me engaged throughout the entire read. The characters were 3 dimensional, meaning they felt really like i wanted to invite over for dinner or just to hang out. Never saw the ending. Im not a tech person, but I found this invention fascinating and was able to follow the tech talk (it was minimal, but even minimal tech talk usually leaves my brain scrambled. Didn't want to put it down and felt a hole in my day when I finished it.
Profile Image for Gareld Butler.
405 reviews4 followers
November 26, 2025
I like this book, and this author. I found the story interesting, and the idea of capturing screenshots and videos from everyone around the world not that big a stretch into science fiction. The facial recognition they describe is already here, and I suspect police departments are further along than we know in being able to stich together videos from the different Ring doorbell cameras in the neighborhood than we realize. I liked Mike Mansfield and his team of "Invisibles", although I can't believe there could ever really be that many around the world that are all connected and available at a moment's notice. In my experience, getting tickets to fly team members all over instantly would never happen.
I found a couple of things the author described in the book to be totally unrealistic. When they went in to the bar/restaurant in Antigua they saw bags of wheat and corn. I have never seen bags of wheat or corn in a restaurant (or home for that matter) in my life. During the chase scene, the author describes the sedan repeatedly ramming the old pickup that Mike was driving. Know old pickups and sedans, after the first ramming, the car would be out of commission with a broken radiator and probably a seized engine while the pickup probably wouldn't have had more than some sheet metal damage to the truck bed. Repeated ramming, and the ability of the sedan to actually flip the pickup on its side seem highly unlikely.
I listened to the audio version and have one comment to make about that. I absolutely HATE listening to Scott Brick's narration. His over-dramatization of absolutely everything really gets on my nerves. I don't think he could order oatmeal for breakfast without drama. Unfortunately, he is the narrator for a large number of thriller/spy novel type books so hearing him is almost unavoidable. There are so many excellent narrators out there that I wish they had chosen someone else.
Profile Image for Makenzie.
50 reviews3 followers
September 20, 2025
This book was a thoughtful recommendation from my Grammy, and I’m glad I gave it a chance. Rollback isn’t my usual kind of read, but it carried a theme that really stuck with me: the idea that later years in life don’t mean a withdrawal from purpose or meaningful contribution. Instead, older folks are given a chance to step back into impactful work—sometimes even on the grandest, most world-shaping scale.

The story blends science fiction with very human questions about aging, identity, and what it means to remain relevant as the world changes around you. I found the concept touching: people in their twilight years being called upon, and trusted, to bring wisdom and perspective to challenges that matter.

While the pacing and genre might not normally draw me in, I appreciated reading it through the lens of my Grammy’s recommendation. It made me reflect on how much value exists in the lived experiences of older generations, and how easily that can be overlooked.

In short, Rollback reminded me that even outside my usual reading preferences, there’s a lot to gain from stepping into someone else’s world—whether that’s a fictional character’s, or the perspective of someone you love and respect.
450 reviews5 followers
August 22, 2025
the story was interesting, but if you don't have a solid base of techno-geek sciences or computer-nerd language and data systems, good luck with all the parsing of digital images, the painting of data systems and the scaping of intelligence from photo sources other than what is right in front of you, specifically in your own hands.
I got lost so many times in the back and forth of who was doing what to the data and ultimately, controlling the actual action in the book, that the story began to fade and the tech overtook my simple mind.
I'm a Google user. A g-mail and YT sort of dabbler, and by no means do I understand any of that stuff. Looking, or trying to look, beyond all the yada-yada-yada of screen systems language I just found the story failed to launch for me.
Not saying it wasn't an interesting book, but I won't do follow on if this is the overall speed the author wants readers to possess.
Profile Image for Melanie Darling.
26 reviews1 follower
August 26, 2025
Very Creative

Three young girls on vacation in the Caribbean are having a great time. Until they aren't... and only two get on the return flight home. I don't usually read 'thrillers' but I genuinely enjoyed this book. I liked the use of technology and AI and how they were woven into the plot, also not something I usually enjoy. I'm definitely not a tech savvy person at all, believe me, so there was just enough of it to make it plausible but not so that it's dry and has me go glassy eyed and put the book down. (I have pre-ordered the next book by Grumley with the same main character and his "group of friends". So there's that) Mike, the protagonist, is a kind of guy " with a certain set of skills" and a dry sense of humour that a few of his associates share. The author gives the reader the respect of not beating us over the head with his characters traits, it's nuanced and believable. Characters are fleshed out and the plot is fast paced and engrossing. A good read.
10 reviews1 follower
August 23, 2025
Holy AARP!

A complete 360 degree turn from your previous books. Mansfield, Hurd, Wanda and the rest off the "invisibles" with their varied talents are a force to be reckoned with! I was immersed in the storyline of how Mansfield and his Crew utilized their resources to assist their "new" client/contacts to locate Bruni's daughter with the assistance of Salazar and The Rollback Machine's technology. The Rollback Machines technology is both inspiring and frightening. Oh, the possibilities of teetering on they precipice of altering Good v. Evil, while patching and piecing together a cornucopia of photographs and digital media with the help of the World' best kept secret. Will the Rollback Machine's glitch be a blessing or a curse?!?! A perfect ending and set-up for The Mirage. I'm a fan of this new cast of characters and their exploits/mission!

Charlie
Profile Image for Robert.
169 reviews12 followers
September 3, 2025
This was my first Michael Grumley novel, and certainly one of his higher rated by numerous reviewers. This novel is about a billionaire, David Bruni, whose daughter disappeared while she vacationed in the Caribbean, who hired a private detective, Mike Mansfield, to help him find / recover her. What made this detective story different were the high and low-tech means by which Mike Mansfield and David Bruni used to uncover her whereabouts.

The high-tech methods that David Bruni used were a creative way to incorporate photos and videos that people spread electronically in the past and present. The low-tech methods used by Mike Mansfield utilized a global network of observant seniors to identify and ensnare wrongdoers.

I thought that the dialogue was good, as were the main characters’ means of ferreting out who did what to whom and when.
407 reviews9 followers
November 27, 2025
Fast paced…great story

First I want to say that I received Rollback from Goodreads as a giveaway.

This is the first book I’ve read by Michael Grumley but definitely not the last. It is the first in a series, and I’m looking forward to book 2. It’s exciting to find an author whose books you really like, so I appreciate being introduced to him by Goodreads and his books are on my “read me” list

The story is fast paced and well developed. I don’t believe in writing a summary of the book as my review, you can find that on Amazon or Goodreads.
Strong characters, unusual twists that keep you guessing. I would have liked a bit more character development, but they are interesting and varied … just would have liked a little more. Definitely worth a read
1 review
August 25, 2025
Michael does it again

It’s not often that an author excites me the way that Michael Grumley does. I’ve devoured every book he has written. He writes with a mix of real world storytelling with just enough “sci-fi” to be plausible. His premises are well researched so that you feel that what he writes could very well happen. Such is the case with Rollback. With AI now more common in the real world, Rollback keeps you turning the pages as you root for the good guys, all while holding your breath that the outcome is as you hope. I can’t wait for Mirage to come out, so that I can see how the next chapter of this journey turns out.
Profile Image for Pamela Sepulvado Sepulvado  Deroche.
278 reviews2 followers
October 13, 2025
The main character Mansfield, I love him. He’s like your favorite Uncle.
Police work in the future can be helped by AI. What if it’s too slow and it can’t keep up. What if it’s everything we need and we become too dependent upon it. But… what if it’s trying to warn you about what can happen and you’re not paying attention.
This story is a futuristic voyage into police work and a great team of unlikely heroes.
Thank you Goodreads for the opportunity to receive my very own kindle copy of this book.
Profile Image for Denny Howard.
155 reviews1 follower
July 17, 2025
I’ve lost count on the number of books Michael has written. But, I’ve read everyone, being enthralled with his prose, style and the roller coaster rides taken. His latest, ‘Rollback’ definitely soars above the others. Not just because of the subject, but his handling of it. It’ll take your breath away! I can’t say anymore without doing it injustice, so I won’t. Get your copy, read it and be a bird, soaring like the eagle I am!
4 reviews
August 16, 2025
Educational as well as interesting

I love the way Michael Grumley writes. He includes such interesting facts and educational history as well as science. He also uses so much detail in describing people and places that I can really visualize his books. They would make great movies. He does not use pages of descriptions. He intertwines the details in the dialogues and actions so it doesn’t get boring.
10 reviews
August 21, 2025
A new favorite author!

OMG! This book has it all! Non-stop action, surprise twists, and excellent characters. I very seldom leave book reviews (too eager to start my next book!). I had to review ROLLBACK because its plot was so unique, leaving me wondering who the bad guy (or woman) was and wondering if the main character around whom the story revolves, survives.
Rollback was an absolute pleasure to read.
Profile Image for William (Mr. Bill) Turner.
439 reviews7 followers
October 17, 2025
Rollback - a next level investigation

This book is a 'next-level' PI case with an unlikely collection operatives all coordinated at the direction of one Mike Mansfield. In a confrontational firs meeting Mansfield is invited to the home of a wealthy businessman with a proposition he finds he can't refuse.
I read this book in one sitting. I could not find a good place to stop. I highly recommend, 'Rollback' by Michael C. Grumley. - Mr.Bill
33 reviews
October 21, 2025
Rollback keeps you enthralled

The book started off somewhat slowly in the first chapter or so but then picked up speed to a great mystery solved. The characters are well depicted, I can see a movie or tv show in my head. Mike Mansfield and his invisible cohorts are super heroes to this old lady. An excellent read, can't wait for the sequel - Mirage - coming in November! Thank you Michael C. Grumley!
Profile Image for B L Lewis.
148 reviews2 followers
November 23, 2025
Pretty Good Book With Likeable Main Characters

Overall I found this to be pretty entertaining. The main characters were likable. The plot, for The most part kept you engaged.

As for the writing, I enjoy Grumbley's style. It was very easy to read.

I gave it a rating of 4 stars out of 5 simply because there were a few points in the book where I wish the author went into detail about what happened, and instead he left it up to our imaginations. That was my only complaint.

236 reviews2 followers
January 1, 2026
Interesting premise

The hero may have some amazing successes but his personality, snarky, taciturn, would normally put off any loyal followers. Yet they are there, standing by, waiting for instructions. To me, that was more unbelievable than the amazing machine which will become another member of his invisible entourage. Rollback may someday be an actuality. It’s not that unlikely.
2 reviews
August 4, 2025
Kept me up late reading this book. Surprising things happen with the use of a new search tool that uses AI to capture everyone's photographs on line to create a timeline of events. After losing hope for a missing daughter they are able to enhance the timeline of events after 4 years to reach an exiting conclusion. Excellent read, Michael wrote this story that keeps you glued to the book.
80 reviews1 follower
August 5, 2025
Riviting

Very original storyline and exceptional characters. I've read slot of Grumley's books but this was different. The use of the variety of characters was unique most of all "THE INVISIBLES". This book kept me engaged the whole way through, not unlike his other books I've enjoyed reading.
120 reviews5 followers
August 10, 2025
I really enjoyed the first book of Michael Grumley's new series. It has a nice balance of scifi and investigative thriller. I also noticed fewer incomplete sentences, which is something that always irked me about this author's style of writing (I think he uses it to build suspense). This is a series I would recommend, and I'm looking forward to the second book coming out later this year.
Profile Image for Aaron.
24 reviews
August 11, 2025
Decent start to a new series

I'm giving it a 3.5 for now. Decent story, with a good topic. It is held back a bit, for me, by some minor issues:
- Plot is a little basic. Feels like a script rather than a book
- Some small translation, grammar, and plot holes. Feels like the editor snoozed over some parts.
Displaying 1 - 30 of 103 reviews

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