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Memento Mori - 111
Four strangers. One shared birthday. A devastating crash. And a device that counts down to their exact moment of death.
Isla, Gareth, Ollie, and Ellie all share the same birthday - 29th February 1992. After narrowly surviving a multi-car pileup on London's Putney Bridge, the four are recruited by Vita, a powerful and secretive biotech corporation, for a highly classified clinical trial. The product? "The Memento". A revolutionary smartwatch that calculates a user's remaining lifespan down to the very second.
As their individual countdowns begin, the trial takes a dark and terrifying turn. From miraculous surgeries to sinister corporate motives, the group soon uncovers that the brilliant but mysterious Dr. Ellisen is hiding a world-shattering secret involving timeline manipulation and the true cost of their survival.
When Vita's ruthless CEO attempts to weaponize the technology, the four test subjects must band together to expose the truth before their own time runs out for good.
A gripping, fast-paced sci-fi thriller exploring mortality, corporate greed, and the ultimate value of time.
Isla, Gareth, Ollie, and Ellie all share the same birthday - 29th February 1992. After narrowly surviving a multi-car pileup on London's Putney Bridge, the four are recruited by Vita, a powerful and secretive biotech corporation, for a highly classified clinical trial. The product? "The Memento". A revolutionary smartwatch that calculates a user's remaining lifespan down to the very second.
As their individual countdowns begin, the trial takes a dark and terrifying turn. From miraculous surgeries to sinister corporate motives, the group soon uncovers that the brilliant but mysterious Dr. Ellisen is hiding a world-shattering secret involving timeline manipulation and the true cost of their survival.
When Vita's ruthless CEO attempts to weaponize the technology, the four test subjects must band together to expose the truth before their own time runs out for good.
A gripping, fast-paced sci-fi thriller exploring mortality, corporate greed, and the ultimate value of time.
502 pages, Kindle Edition
Published June 1, 2026
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June 8, 2026
Four strangers:
Isa - working as a lawyer but dreaming of a career as an artist, stuck in a destructive relationship.
Gareth – Ex-footballing golden boy, whose career was cut short by a knee injury that wont heal, slowly drinking himself to death
Ollie – anxious, feeling isolated and dragged along by his larger than life friend Tom
and Ellie – CEO and founder of Vita, working herself into an early grave and not spending nearly enough time with her ageing and ailing parents.
Tied together by their shared birthday, 29.02.92 and thrown together after barely surviving a multi car pile up, they are recruited by the mysterious biotech firm, Vita, to take part in a secret trial. Each of them will be given a revolutionary smartwatch that shows them their remaining lifespan down to the very second. As the trial begins they learn that their actions directly affect the numbers on the watch, sometimes for the better and sometimes for the drastically worse. As each of them take steps to better themselves in an attempt to increase their longevity, the trial takes a terrifying turn, and the four start to realise that the man leading the research, Dr Ellison is hiding a devastating secret involving multiple timelines and the true cost of each of their lives. A new CEO has taken over Vita and is determined to weaponise the the technology, the group realise they must use the information learned from Dr Ellison and expose the truth before everyone time runs out – for good.
I was offered an advanced copy of this by the author and all I had to go on was the short description he gave me. Sci-fi, thriller, time travel, mystery – this book had all the ticks, and I definitely wasn’t disappointed. The idea of knowing exactly when you were going to die, and knowing there were steps you could take to extend it was a fascinating concept to me, reminds me a lot of the film In Time, but with the time travel element thrown in.
The four people selected for the trial couldn’t have been more different, and it was really interesting to see how their wildly different personalities meshed together to create a fairly formidable team. What was also really fascinating to me was the characters individual growth once they learned about how their actions affected their time, and how their relationships with each other and those around them developed. Each of them go through some pretty incredible changes from how they were living their lives at the start of the book.
This is definitely a book that keeps you on your toes, all the way through you absolutely cannot guess what the big secret is going to be, and this is a massive bonus to me as quite often thrillers can be very predictable. It’s incredibly fast paced and I didn’t want to put it down, each chapter giving you jussssst enough information to leave you turning the pages to get more.
The ending left me emotionally wrecked, I absolutely did not see the outcome happening the way it did and that little teaser of what's to come has left me harassing the author for news of the next ones release!
Often indie authors don’t get the credit they deserve, and this is one that needs everyone shouting from the rooftops about his incredible writing.
Isa - working as a lawyer but dreaming of a career as an artist, stuck in a destructive relationship.
Gareth – Ex-footballing golden boy, whose career was cut short by a knee injury that wont heal, slowly drinking himself to death
Ollie – anxious, feeling isolated and dragged along by his larger than life friend Tom
and Ellie – CEO and founder of Vita, working herself into an early grave and not spending nearly enough time with her ageing and ailing parents.
Tied together by their shared birthday, 29.02.92 and thrown together after barely surviving a multi car pile up, they are recruited by the mysterious biotech firm, Vita, to take part in a secret trial. Each of them will be given a revolutionary smartwatch that shows them their remaining lifespan down to the very second. As the trial begins they learn that their actions directly affect the numbers on the watch, sometimes for the better and sometimes for the drastically worse. As each of them take steps to better themselves in an attempt to increase their longevity, the trial takes a terrifying turn, and the four start to realise that the man leading the research, Dr Ellison is hiding a devastating secret involving multiple timelines and the true cost of each of their lives. A new CEO has taken over Vita and is determined to weaponise the the technology, the group realise they must use the information learned from Dr Ellison and expose the truth before everyone time runs out – for good.
I was offered an advanced copy of this by the author and all I had to go on was the short description he gave me. Sci-fi, thriller, time travel, mystery – this book had all the ticks, and I definitely wasn’t disappointed. The idea of knowing exactly when you were going to die, and knowing there were steps you could take to extend it was a fascinating concept to me, reminds me a lot of the film In Time, but with the time travel element thrown in.
The four people selected for the trial couldn’t have been more different, and it was really interesting to see how their wildly different personalities meshed together to create a fairly formidable team. What was also really fascinating to me was the characters individual growth once they learned about how their actions affected their time, and how their relationships with each other and those around them developed. Each of them go through some pretty incredible changes from how they were living their lives at the start of the book.
This is definitely a book that keeps you on your toes, all the way through you absolutely cannot guess what the big secret is going to be, and this is a massive bonus to me as quite often thrillers can be very predictable. It’s incredibly fast paced and I didn’t want to put it down, each chapter giving you jussssst enough information to leave you turning the pages to get more.
The ending left me emotionally wrecked, I absolutely did not see the outcome happening the way it did and that little teaser of what's to come has left me harassing the author for news of the next ones release!
Often indie authors don’t get the credit they deserve, and this is one that needs everyone shouting from the rooftops about his incredible writing.
Review of advance copy received from Author
🌟 3.75 stars, rounded up 🌟
"Philosophically speaking, death is the ultimate catalyst for living a full life."
I was drawn to this book because of the unusual subject matter, and was excited to find out how it was handled. Imagine if you could just know how long you had left to live - would you look? How would you deal with knowing? What would you change in your life?
I definitely wasn't disappointed - the plot is twisty and turny and endlessly surprising! The small (and big!) twists were brilliant, and kept me absolutely gripped all the way through.
I enjoyed the UK setting, and also the mysterious way our four characters were introduced to us. Their individual growth, and relationships throughout the book were interesting, and had me really rooting for them all. I didn't feel a particular connection to any of them, and it felt like their personalities were sometimes a bit inconsistent, but obviously they're all going through an extremely traumatic time so it could well just be that! Gareth was my favourite (seems to be a common theme in other reviews also!) - I think he came across as the most genuine, honest person and also his growth through the story was beautiful.
All the different threads of plot and different people's backstories became a bit confusing at times, but I enjoyed the way it kept me on my toes, and had me trying to figure things out even when I wasn't actively reading it!
For me it felt like there were a few issues with continuity in certain things, which took me out of the story when I was scrolling back and forth trying to match things up. However, with such an intricate, cleverly planned story, I imagine this is difficult to completely avoid, and none of them were major things (I think I'm just particularly pernicketty when it come to things making total sense in my head!)
The conclusion was a surprise to me, and left unanswered questions to get you to dive straight into book #2 when it comes out. I hope our four characters still play a major role in it, as I'd love to see even more growth for them, and maybe some time to just enjoy their lives, once this is over for them.
I can't imagine anyone not getting something from this story - whether you're into sci-fi or not, the premise is just fascinating. If you're going to read it, I'd say set aside a whole day, because you won't be able to put it down ;-)
"Time becomes precious not when we know exactly how much we have left, but when we stop wasting what we have now."
"Philosophically speaking, death is the ultimate catalyst for living a full life."
I was drawn to this book because of the unusual subject matter, and was excited to find out how it was handled. Imagine if you could just know how long you had left to live - would you look? How would you deal with knowing? What would you change in your life?
I definitely wasn't disappointed - the plot is twisty and turny and endlessly surprising! The small (and big!) twists were brilliant, and kept me absolutely gripped all the way through.
I enjoyed the UK setting, and also the mysterious way our four characters were introduced to us. Their individual growth, and relationships throughout the book were interesting, and had me really rooting for them all. I didn't feel a particular connection to any of them, and it felt like their personalities were sometimes a bit inconsistent, but obviously they're all going through an extremely traumatic time so it could well just be that! Gareth was my favourite (seems to be a common theme in other reviews also!) - I think he came across as the most genuine, honest person and also his growth through the story was beautiful.
All the different threads of plot and different people's backstories became a bit confusing at times, but I enjoyed the way it kept me on my toes, and had me trying to figure things out even when I wasn't actively reading it!
For me it felt like there were a few issues with continuity in certain things, which took me out of the story when I was scrolling back and forth trying to match things up. However, with such an intricate, cleverly planned story, I imagine this is difficult to completely avoid, and none of them were major things (I think I'm just particularly pernicketty when it come to things making total sense in my head!)
The conclusion was a surprise to me, and left unanswered questions to get you to dive straight into book #2 when it comes out. I hope our four characters still play a major role in it, as I'd love to see even more growth for them, and maybe some time to just enjoy their lives, once this is over for them.
I can't imagine anyone not getting something from this story - whether you're into sci-fi or not, the premise is just fascinating. If you're going to read it, I'd say set aside a whole day, because you won't be able to put it down ;-)
"Time becomes precious not when we know exactly how much we have left, but when we stop wasting what we have now."
June 4, 2026
"Memento Mori. Remember that you must die. On a long enough timeline, the survival rate for everyone drops to zero."
Four people celebrating their thirty second birthday: 29/02/24 - 18:00.
Isla
Successful lawyer who started as an artist. She decides to participate in the study because she needs the money they offer her.
Ellie
Youngest female CEO of a tech company in Silicon Valley. Her company developed the watch that will be used for the experiment.
Ollie
Works as a programmer in Ella's business. Has crippling anxiety and has caused an accident.
Gareth
Former football player who had a career ending injury. He's recycled himself as a pill popping alcoholic
They were all asked to participate in a study that will let them know how long they have left to live. They are all given a watch that tells them how much time they have left. As the book progresses, their times go up or down, depending on what is happening in their lives. That pushes them to make different life choices and engage in activities that they might not have if they weren't wearing the watch.
This book is a reminder that we must focus on making the best of what life has to offer us. That it's not about how long we live but about what we did with what we had.
I loved this book so much. Not only because of the message that it is trying to transfer but also for the story itself. I can't wait to know what happens in the second book.
"Time becomes precious not when we know exactly how much we have left, but when we stop wasting what we have now."
Four people celebrating their thirty second birthday: 29/02/24 - 18:00.
Isla
Successful lawyer who started as an artist. She decides to participate in the study because she needs the money they offer her.
Ellie
Youngest female CEO of a tech company in Silicon Valley. Her company developed the watch that will be used for the experiment.
Ollie
Works as a programmer in Ella's business. Has crippling anxiety and has caused an accident.
Gareth
Former football player who had a career ending injury. He's recycled himself as a pill popping alcoholic
They were all asked to participate in a study that will let them know how long they have left to live. They are all given a watch that tells them how much time they have left. As the book progresses, their times go up or down, depending on what is happening in their lives. That pushes them to make different life choices and engage in activities that they might not have if they weren't wearing the watch.
This book is a reminder that we must focus on making the best of what life has to offer us. That it's not about how long we live but about what we did with what we had.
I loved this book so much. Not only because of the message that it is trying to transfer but also for the story itself. I can't wait to know what happens in the second book.
"Time becomes precious not when we know exactly how much we have left, but when we stop wasting what we have now."
Review of advance copy received from Author
4.5 rounded up.
This book has really taken me by surprise.
I don’t usually read thrillers but this really intrigued me.
I guess I have a morbid curiosity because of the loss I’ve experienced in my life.
Would you want to know how long you had left to live? Would you want to know how long others had to live?
I like the thought that making good choices prolongs your life when I think of some choices that I’ve made.
The book was fast paced and easy to read, I finished it within a couple of reading sessions. It kept me gripped and wanting to know more.
I could never have predicted the major plot twist and that’s a big selling point for me as a lot of books are so predictable.
I enjoyed the development of certain characters in this book, Gareth ended up becoming my favourite.
I wish the romantic connection had been explored a little more as it felt like it almost came from no where but it was really important to the storyline so I’m glad it was there.
I was emotionally wrecked by the end. It hit a bit too hard to home for me but I’m looking forward to book two.
Thank you for offering me the ARC for this book Matt
This book has really taken me by surprise.
I don’t usually read thrillers but this really intrigued me.
I guess I have a morbid curiosity because of the loss I’ve experienced in my life.
Would you want to know how long you had left to live? Would you want to know how long others had to live?
I like the thought that making good choices prolongs your life when I think of some choices that I’ve made.
The book was fast paced and easy to read, I finished it within a couple of reading sessions. It kept me gripped and wanting to know more.
I could never have predicted the major plot twist and that’s a big selling point for me as a lot of books are so predictable.
I enjoyed the development of certain characters in this book, Gareth ended up becoming my favourite.
I wish the romantic connection had been explored a little more as it felt like it almost came from no where but it was really important to the storyline so I’m glad it was there.
I was emotionally wrecked by the end. It hit a bit too hard to home for me but I’m looking forward to book two.
Thank you for offering me the ARC for this book Matt
Review of advance copy received from Author
I received an advance reader copy of this book by the author.
Memento Mori by M. King was such a gripping surprise, I tore through it in two sittings because the pacing never lets up. The premise alone hooked me: four strangers, one shared birthday, a near‑fatal crash, and a biotech device that counts down to the exact moment of your death. But what really impressed me was how well the story delivered on that concept.
I loved the multi‑POV format. Switching between Isla, Gareth, Ollie, and Ellie kept the tension sharp and made the stakes feel personal. Each character is battling their own demons, and the book gives them space to grow in ways that feel earned rather than rushed.
The plot moves quickly, but not at the expense of clarity. The twists near the end genuinely shocked me. I didn’t see them coming at all and the final chapters set up a sequel in a way that feels exciting rather than gimmicky.
A clever, fast‑paced sci‑fi thriller with heart, high stakes, and a concept that’s both unsettling and addictive. I received this as an advance reader copy, and I’m already eager for book two.
Memento Mori by M. King was such a gripping surprise, I tore through it in two sittings because the pacing never lets up. The premise alone hooked me: four strangers, one shared birthday, a near‑fatal crash, and a biotech device that counts down to the exact moment of your death. But what really impressed me was how well the story delivered on that concept.
I loved the multi‑POV format. Switching between Isla, Gareth, Ollie, and Ellie kept the tension sharp and made the stakes feel personal. Each character is battling their own demons, and the book gives them space to grow in ways that feel earned rather than rushed.
The plot moves quickly, but not at the expense of clarity. The twists near the end genuinely shocked me. I didn’t see them coming at all and the final chapters set up a sequel in a way that feels exciting rather than gimmicky.
A clever, fast‑paced sci‑fi thriller with heart, high stakes, and a concept that’s both unsettling and addictive. I received this as an advance reader copy, and I’m already eager for book two.
May 19, 2026
If you love John Marrs books then you will absolutely love this! I was intrigued from the very beginning with the characters as they were all so different and deep. I honestly forgot that I was reading while reading this because it was so immersive and I just couldn’t wait to pick it back up. There were some extremely thought provoking moments throughout the book that really made me stop and think wha I would do in this situation. I also love the uk setting and the characters really resonate with me since I am also from England. There was a great twist towards the end that I would never have predicted and I found myself really rooting for the characters. I already can’t wait for the next book!
Review of advance copy received from Publisher
This book really makes you stop and think about time in a completely different way. It explores the idea of knowing exactly how much time we have left and how that kind of knowledge could change the way we live, love, and connect with others.
It made me wonder if people would love harder, worry less, be more present, and forgive faster if we truly understood how limited time really is. Most of us move through life assuming we have more time than we actually do, and this story challenges that mindset in such an emotional and thought provoking way.
The book was heartbreaking, beautiful, and deeply reflective. More than anything, it felt like a reminder not to take moments, people, or even ordinary days for granted.
It made me wonder if people would love harder, worry less, be more present, and forgive faster if we truly understood how limited time really is. Most of us move through life assuming we have more time than we actually do, and this story challenges that mindset in such an emotional and thought provoking way.
The book was heartbreaking, beautiful, and deeply reflective. More than anything, it felt like a reminder not to take moments, people, or even ordinary days for granted.
Review of advance copy
This was such a good read! I really liked all of the characters, learning more about them and their stories.
I think that the way the book was written was really well done, with the pacing done correctly, and reminders of the watch times were frequent enough. Each character felt like they had an equal amount of chapters from their points-of-view and I liked the meeting/journal chapters to see the characters talking about the events of their lives and learning about each other too!
The twists and turns in this book were really exciting and unexpected! The ending was thrilling too and I can't wait for a sequel!
I received a free copy of this book via Booksprout and am voluntarily leaving a review.
I think that the way the book was written was really well done, with the pacing done correctly, and reminders of the watch times were frequent enough. Each character felt like they had an equal amount of chapters from their points-of-view and I liked the meeting/journal chapters to see the characters talking about the events of their lives and learning about each other too!
The twists and turns in this book were really exciting and unexpected! The ending was thrilling too and I can't wait for a sequel!
I received a free copy of this book via Booksprout and am voluntarily leaving a review.
Review of advance copy
If you are a fan of dystopian soft sci-fi, refreshing writing techniques and fatally flawed yet heroically human characters momento mori is a must read.
It has mystery, suspense, thrill, realistic romance, and an utterly absurd unpredictable plot twist that would ordinarily be groan worthy and yet works so well within this world. And I really mean completely unpredictable.
My only regret reading this book is the length of time I must wait for a sequel.
An absolute masterpiece of an easy, yet gripping read, in my humble opinion.
I received a free copy of this book via Booksprout and am voluntarily leaving a review.
It has mystery, suspense, thrill, realistic romance, and an utterly absurd unpredictable plot twist that would ordinarily be groan worthy and yet works so well within this world. And I really mean completely unpredictable.
My only regret reading this book is the length of time I must wait for a sequel.
An absolute masterpiece of an easy, yet gripping read, in my humble opinion.
I received a free copy of this book via Booksprout and am voluntarily leaving a review.
August 17, 2026
I loved the concept of Memento Mori 111 - how would you live your life if you knew exactly how much time was left?
The characters were engaging, and I really enjoyed following their developments and the way their relationships changed from being part of the same experiment.
I thought I knew exactly where the story was headed but was pleasantly surprised by one of the twists and the ending, too.
The technology and science were innovative and imaginative and although not the first genre I would go for, this was a really interesting, easy read.
I will definitely be reading the following books!
The characters were engaging, and I really enjoyed following their developments and the way their relationships changed from being part of the same experiment.
I thought I knew exactly where the story was headed but was pleasantly surprised by one of the twists and the ending, too.
The technology and science were innovative and imaginative and although not the first genre I would go for, this was a really interesting, easy read.
I will definitely be reading the following books!
Review of advance copy received from Author
This book is something, I didn't expect to love it so much.
When I saw it on the socials of this author, I was really intrigued by it.
Honestly, I can't stop thinking about it, and what should I do in they're place, would I want to know when I am going to die, if I have years, months, days rest to live my life. I really don't know if I would want to know.
This story is well written, sometimes it is a little emotional roller coaster, I am really intrigued to know the rest of it.
It was a really fast read and a great read.
When I saw it on the socials of this author, I was really intrigued by it.
Honestly, I can't stop thinking about it, and what should I do in they're place, would I want to know when I am going to die, if I have years, months, days rest to live my life. I really don't know if I would want to know.
This story is well written, sometimes it is a little emotional roller coaster, I am really intrigued to know the rest of it.
It was a really fast read and a great read.
Review of advance copy received from Author
I am not exaggerating when I say I could not put this book down!! The story was right up my street and it was easy to follow, even with the multiple POVs. I really cared about what happened to each of the characters and was desperate to know what was going on! I went through so many different emotions reading this book which I didn't expect going in and the ending was really good. I will be thinking about this one for a long time.
May 12, 2026
5⭐️ I absolutely devoured this!! If you’re a fan of Blake Crouch / John Marrs, then you will love this multiple POV, near-future book! I was gripped the whole way through and felt connected to all of the characters, whilst having my mind blown by the plot twist!!! I never would have guessed it. I’m so happy that there’s going to be a sequel to continue this story and I already cannot wait to read it!
June 30, 2026
The characters each seem to have an important role in unraveling the mystery, while the biotech setting adds a modern and believable edge to the science fiction elements. Overall, this sounds like an engaging page-turner that will appeal to readers who enjoy intelligent thrillers with high stakes and philosophical questions.
A compelling concept, intriguing characters, and an exciting blend of science fiction and suspense make this a memorable and worthwhile read.
A compelling concept, intriguing characters, and an exciting blend of science fiction and suspense make this a memorable and worthwhile read.
Review of advance copy received from Author
I absolutely loved this book! I devoured it in a couple of sittings, it was hard to put down. I loved the characters, the story and the way in which the story is written. I consider myself as an armchair detective, I can usually tell in advance what will happen etc but the twist at the ending I had no idea!! I cannot wait to preorder a physical copy, it’s worthy 100% and to read the next one! Would definitely recommend:)
Review of advance copy received from Author
I’m already calling it in as my favourite book of the year and would rate it more than 5 stars if it was possible.
The near future technology is quite terrifying and it really makes you think how you should be making the most of your life! The characters are likeable, even Gareth! And the storyline is gripping. Fantastic work Matt, can’t wait for more!
The near future technology is quite terrifying and it really makes you think how you should be making the most of your life! The characters are likeable, even Gareth! And the storyline is gripping. Fantastic work Matt, can’t wait for more!
June 1, 2026
I was lucky enough to be given access to this book before it was released and I'm so glad I was! I devoured this book so quickly I couldn't believe it was 500 pages long. Very gripping storyline with a hell of a plot twisy that is perfect for fans of John Marrs and Black Mirror- it was released only 24 hours ago and I'm very eagerly awaiting the next one!
August 1, 2026
4 strangers linked together by the same birthday - who all ended up in a multicar car crash.
They become part of biotech firm trial - each has a smartwatch which shows their remaining life span. What would you do if you had that knowledge??
Gripping story full of twist and turns. Couldn’t put it down
They become part of biotech firm trial - each has a smartwatch which shows their remaining life span. What would you do if you had that knowledge??
Gripping story full of twist and turns. Couldn’t put it down
This entire review has been hidden because of spoilers.
June 2, 2026
I really loved this book. I was completely invested in the characters and their journey with the Momento watch. I especially loved Gazza. He's definitely my favourite. Just when you think you've figured it out another twist. Really look forward to reading the next one.
June 10, 2026
Love this book from beginning to end and cannot wait for second. It was such fast-paced, so unpredictable in the plot, definitely not expected that but such interesting story raising questions more and more. My anxiety had anxiety)))
Review of advance copy
Leaving a review for this amazing book.
Received a copy from Booksprout and I must say it exceeded my expectations. Very excited for this to come out and have it on my shelf ☺️
Received a copy from Booksprout and I must say it exceeded my expectations. Very excited for this to come out and have it on my shelf ☺️
Review of advance copy received from Author
This book is different to anything I’ve ever read. It was a fast paced, addictive storyline. I loved the characters and the plot. I didn’t enjoy one part of the twist but the rest of the book makes up for that. It was emotional at times but I like that aspect of a book. Can’t wait to read the other ones when they come out!
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