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Mark Dawson’s Group Fifteen Files. Quick, lightning-paced, action from the first page to the last.

Bjorn Thorsson joined the Special Air Service to forget the horrors of his childhood. He killed for Queen and country, and he was good at it.

He quits the army and settles down, looking for a quieter life. When his beautiful sister Gudrun finds herself in trouble with the owner of a hedge fund, Bjorn promises to get her out of danger. But there’s another factor in play. Group 15, a clandestine government agency, has plans for the financier, and Bjorn is in their way.

Bjorn must outwit the Group in the streets of London and in the Highlands of Scotland if he is to protect his sister and survive.


Praise for Mark Dawson:

"It’s impossible not to think of Lee Child’s super-selling Jack Reacher. " - The Times

"A literary sensation." - The Daily Telegraph

"Dawson writes the kind of thrillers I love. Non-stop, grab-you-by-the-throat tales of doing the right thing no matter the odds. Simply excellent." - USA Today bestselling author Brett Battles


Praise for Michael Ridpath:

“Michael Ridpath is on the war path, trouncing the Scandinavians on their home turf. This is international thriller writing at its best, fine characters, page turning suspense and a great, fresh location.” — Peter James

“One of our finest thriller writers.” — The Daily Mail

“Ridpath has the read-on factor that sets bestsellers apart.” — The Guardian


More than 1m copies sold in the John Milton and Beatrix Rose series and 1000s of five star reviews.

126 pages, Kindle Edition

First published March 12, 2018

652 people are currently reading
209 people want to read

About the author

Mark Dawson

114 books1,853 followers
For news and special offers join Mark's mailing list at:

http://eepurl.com/Cai5X

Mark Dawson was born in Lowestoft and grew up in Manchester and Chicago. He has worked as a lawyer and currently works in the London film industry. His first books, "The Art of Falling Apart" and "Subpoena Colada" have been published in multiple languages.

He is currently writing two series. Soho Noir is set in the West End of London between 1940 and 1970. The first book in the series, "The Black Mile", deals with the (real life but little known) serial killer who operated in the area during the Blitz. "The Imposter" traces the journey of a criminal family (think The Sopranos in austerity London and you'd be on the right track).

The John Milton series features a disgruntled special agent who aims to help people to make amends for the terrible things that he has done. Mark, as a child of the 80s, will freely admit that he watched a lot of The Equalizer in his youth.

Mark lives in Wiltshire with his family.

You can find him at www.markjdawson.com or www.facebook.com/markdawsonauthor.

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5 stars
512 (44%)
4 stars
432 (37%)
3 stars
181 (15%)
2 stars
30 (2%)
1 star
6 (<1%)
Displaying 1 - 30 of 79 reviews
Profile Image for Terence M [on a brief semi-hiatus].
696 reviews369 followers
January 1, 2022
1-Star - "I Did Not Like It"
Mark Dawson, with Michael Ridpath
Narrator: David Thorpe
Audio novella - 03:16 Hours - DNF@76%

From my Reading activity:
03:16 Hours - Heard: 01:35 - Balance: 01:41 Hours
"I started to lose track of this story within the first 15 minutes.
I can only hope it improves!"

03:16 Hours - Heard: 02:29 Hours - Balance: 00:57 Hours
"My best intention was to finish listening to this audio-novella, but I couldn't!
So it is a dnf @ 76%."


My suspicion is that Michael Ridpath must have been the primary writer of this story.
I cannot understand why an author such as Mark Dawson would allow this piece of junk to carry his own name.
Profile Image for Jennifer.
906 reviews53 followers
September 15, 2021
Another intense novella. Lots of drama but not all that much feeling. One downside of a shorter book. There was plenty of action and it was a good cleanse before jumping into something longer 😉
Profile Image for Kathi Defranc.
1,182 reviews498 followers
March 13, 2018
What a great adventure featuring some in Group 15 and some businessmen who are killing ex-employees who try to blackmail them! All the suspense and fast-paced action we are used to in this author's stories, and we get to meet a possible new 'hero' coming to the Group.
Could not stop reading and was able to finish quickly- the only problem with these great books, because now I have to wait for the next!!
Profile Image for David Highton.
3,757 reviews32 followers
May 16, 2018
Another novella from Group Fifteen, post-John Milton and pre-Isabella Rose. As usual, the story features assassins, both private and state-sponsored, with two American businessmen at the contre of the narrative with some strong personal motivation coming into play.
Profile Image for Richard.
2,328 reviews196 followers
November 13, 2020
More killing from the records of Group 15. Milton is mentioned and there are lots of books featuring John Milton’s abilities by this author that you may know. This is a short story of that special ilk that will interest you. New readers, beware, this author writes in a way any fan of this genre of action based thrillers will feel compelled to read on and devour all his many works.
This is a great story. It reveals yet more aspects of this secretive government agency that kills for its country and has agents who can be disowned if caught.
Here the duplicity of national interests has the government protecting an American hedge fund specialist who is not a nice man. But orders are orders there is no room for sentiment and failure can lead to dismissal from the service. A career you do not retire from or stand down. If your services are no longer required your contract is not the only thing terminated.
It is a story all about risk in a one to one situation. Your assessment of that other person, calling their bluff or following your own gut instincts. It is the difference between life and death, success and failure but not the blurred lines of right and wrong.
These individuals work outside the law. Place their trust in others or survive on personal belief and a degree of self confidence.
This book recounts a number of these duals where money and power initially hold sway. But Dawson goes on to explore deeper motives and more genuine responses to human life.
The power of family whether blood or in service, a sense of debt and guilt. To kill on demand to an order is what Control expects of his operatives. Milton spectacularly loss his way; here in this short story similar emotions are released and a different outcome is required to prevent injustice. Who is able to make that call, what are the consequences if you hesitate rather than following orders.
I really liked that these human issues were explored rather than the victor simply being the better trained, the biggest gun or the good guy working for the British government. I like that the author blurs these lines and in the process writes a sharper and more believable narrative.
Profile Image for Marika Charalambous.
606 reviews28 followers
December 28, 2018
It's been a while since I've read this novella, but I forgot to review it. It was quite short, I started reading something else right after, and it got lost in the process.

Little Sister is the third book in the novella series, and it gives a bit more background info on the famous clandestine group of assassins.

As the book was left sort of open ended, I wouldn't mind seeing a new series featuring Bjorn Thorsson. He is definitely an intriguing character, and I'd be curious to see how Group Fifteen would try (or succeed?) to break his integrity. Because Group Fifteen is good at that, but still, there are people like John Milton who decide enough is enough. What would Bjorn Thorsson do?

Full review: https://mysterysequels.com/book-revie...
Profile Image for Abibliofob.
1,595 reviews102 followers
March 30, 2021
Little Sister introduces Bjorn Thorsson who will later in life hunt John Milton on order of the new "Control" This is another great adventure by Mark Dawson. This time we get to know Bjorn who is teaching nordic languages in England when suddenly his sister is in deep trouble. Is her boyfriend a murderer or not? The entire Group Fifteen Files series can be seen as a prequel to the other series about Milton and the 2 Roses. Highly recommended.
Profile Image for Brandi.
148 reviews8 followers
March 19, 2018
I truly give this 4.75 stars, because I'm still not 100% sure about the Group 15 novellas. I do like them, but find them a tease - this one took a little while to convince me that I should stick with it, but oh gosh, the ending! I see so many possibilities here - a new series with Bjorn, perhaps, Mark? I received this book in exchange for an honest review.
Profile Image for Kevin.
877 reviews41 followers
October 23, 2018
Interesting

Interesting collaboration of two authors who have seamlessly written a really good, fast paced yet at the same time, sedate novella. The opening gambit was intriguing as I felt that the story was going to open there however was pleasantly surprised that it didn't and opened later on.
Profile Image for Larry.
172 reviews
February 10, 2019
Little Sister is the last in Volume 1 of the Group Fifteen Files and has probably the least written about them. Usually, the protagonist is a member of Group Fifteen and the antagonist is a mercenary or government agency with an agent in Britain that was up to no good. This time we find Finley Karsh, the owner of a hedge fund company called Lochalsh Capital, being blackmailed by a former employee or at least attempted to be blackmailed but Karsh knows how to handle the situation, and he handles it with a historical luger. He handles it with murder. Karsh is in accompaniment with his right-hand man Jesse Brunner and their girlfriends Olya and Gudrún. Olya gets suspicious and leaves her boyfriend Jesse when they return to London, but she cannot persuade Gudrún.to leave Karsh. Keeping up?

Now enter the hero of our story, the big, and I mean big brother of Gudrún, an Icelandic native and former British SAS member Björn Thorsson now getting his masters at University College London studying old Norse and doing some language classes on the side. Enter Olya, a woman he never liked because of her influence on his younger sister, to get him to talk Gudrún into leaving Karsh.

Now to convolute my review more Karsh has a contract out on him from a rival mining company because they are both bidding on some mining project in a country nobody has ever heard of, so Group Fifteen is called in to protect Karsh, kill the mercenary with a 100% kill rate record and in the end save Queen, Country and the British way of life.

No more spoilers, the book is only 126 pages and takes a little over a couple of hours to read. Mark and Mark cram a lot into this little book and it comes out to be like the other books in this series, a little better than average read.

As for the books, if you have Kindle Unlimited you borrow the books for free or for a limited time buy the Volume for only 99 cents, which I did. I wonder who gets the 99 cents?

I rate this book 3 stars. Like I said it is a good read worth reading if you are into this genre,

Little Sister by Mark Dawson w/ Mark Ridpath
A Group Fifteen Novella (Group Fifteen Files Book 3)
23 reviews3 followers
March 18, 2018
Disappointing in many respects

I should begin by saying I am a huge Mark Dawson fan... I've read everything he's written and have loved it all with the exception of this book. I almost don't know where to begin because this is so far removed from everything is written before that I've almost concluded he had very little to do with the writing. The people aren't especially believable, I find the descriptive passages wordy and lacking in the kind of exciting capturing of a location that I find him to be particularly good at doing. ( that's a terrible last sentence but I hope you get the point.) There wasn't a single character in this book that I felt particularly attracted to or that I thought was fleshed out and while emotions were sometimes described as attaching to one of the characters I didn't feel it... not at all. Well I haven't read the co-author I see he's very well respected and extremely popular so perhaps it's his style that I'm seeing that I'm really not attracted to. I will always read Mark Dawson's books but if there are any more in this series I think I will pass.
Profile Image for Greg Strom.
407 reviews
May 31, 2025
Hardly qualifies for a book being an hour or so long listen, but though I like narrator Thorpe and Dawson this story was weak and belonged on cutting room floor. Bjorn big Icelandic dude has sister Gorgon who is going out with sketchy rich guy Karsh who sounds like Kash making me instantly dislike and distrust him, so many money grubbers out there. He has weak reason to fear for life , some mining deal, Control (hello Pope, I do like you) has to protect him so England can get some $ but Gorgon blabs like an idiot that Karsh is a killer and gets offed....did I mention big dude is the brother? So now this sucks cause the good people aren't supposed to get shot multiple times in head, especially beautiful women so Bjorn now has to avenge sister, has awkward sleep over with her equally concerned and hot girlfriend (go figure) and meets group 15 en route to revenge. Well all well that ends well except of course for poor Gorgon and group 15 gets bested and decides to hire the guy even after he gives Karsh what he deserves even though he wasn't the actual trigger man. At least my camping trip was awesome and I wasn't relying on this for my weekend entertainment !
This entire review has been hidden because of spoilers.
Profile Image for Pete.
895 reviews7 followers
March 13, 2018
The Group 15 novellas, collaborations between Mark Dawson and other thriller writers (in this case Michael Ridpath) are very interesting for Mark Dawson fans, as they bring a slightly different angle and style to the books, but still maintain the quality.
Little Sister is a very good book, it introduces a new character, Bjorn Thorsson, who has the potential to add a new dimension to the Group 15 stories, the writing is excellent and the action passage towards the end of the book is excellent.
One slight issue with this book for me, was that the introduction and build up took up too much of the book, it was almost as though these parts were written for a full-length book and then the rest of the story shoe-horned in to the novella template, I think that this may have been partly because a new character needed to be introduced. This is why I have docked it one star. But, it's still a great read and hopefully new readers will enjoy it enough to read more of Mark's work.
I received an ARC from the author, but this honest review is voluntarily written and based on my own opinions.
Profile Image for Neelabh Pratap  Singh.
Author 43 books26 followers
March 20, 2024
"Little Sister," the latest Group 15 novella, introduces readers to Bjorn Thorsson, a former SAS operative, and unfolds a gripping tale of vengeance, intrigue, and covert operations. After his sister, Gudrun, is murdered for suspecting her boyfriend, hedge fund manager Finlay Karsh, of a heinous crime, Bjorn is consumed by the need for retribution. The narrative takes a complex turn as Karsh's unexpected significance to the British government brings Group 15 into play, tasked with protecting him against an imminent assassination threat.

Set against the dramatic backdrop of a Scottish castle, the story masterfully weaves together the paths of three assassins hidden in the surrounding woods: one aiming to eliminate Karsh, another targeting the first assassin, and Bjorn, driven by personal vendetta. The ensuing cat-and-mouse game is thrilling, with strategic maneuvering and suspense that keeps readers on the edge of their seats.
Profile Image for Simon Howard.
356 reviews
March 16, 2018
Calm and measured Bjorn Thorsson spends his days teaching and working on his masters degree, a far cry from the 6.4ft Icelanders time in the SAS. But when he gets word his younger sister is in trouble mixed up with an owner of a hedge fund and some truly dodgy dealings he sets out to rescue her and bring about his own form of justice, the problem is this brings him into direct conflict with Group 15 who for their own reasons want the hedge fund owner very much alive....soon the action spills out from London to the Highlands of Scotland as an immovable object meets an irresistible force and this time Group 15 might of bitten off more than they can chew. Atmospheric, well paced with interesting characters the story moves along to an action packed satisfying conclusion. I really really hope that we see more of Bjorn Thorsson, who is a wonderful new character.
Profile Image for RJ.
2,044 reviews13 followers
October 5, 2021
Bjorn Thorsson is a former SAS operator. He retired and spends a quiet life teaching Icelandic languages at the University. His younger half-sister Gudrun loves the University is free-spirited and loves to have fun. Her roommate, Olian is Russian-born and has no money problems. The two of them joined up with Finley, the head of a hedge fund, and his partner Jessie. When you work for Finley, if you fail in your trading, you tend to disappear. Olian has come to Bjorn to warn him that Gudrun is in trouble. Bjorn wanted to take Gudrun away from Finley but she resisted. Unknown to all, Group 3 had Finley under surveillance. Political dealings brought Group 15 into the picture. Bjorn, Gudrun, and Olian are in the middle of a covert operation, and in the way. The characters are interesting and realistic, the plot could be from today’s headlines.
Profile Image for Melanie.
500 reviews16 followers
July 20, 2020
A short story in three parts. The author spent too much time building up villain character in the first half, leaving the final denouement too short and abrupt. The meat was just beginning to form into McNair and Thorsson and this could have been made more exciting if it ran for just a couple of pages more to complete a final case. The end was slightly unbelievable. I guess I'm complaining about wanting more, yes. To give justice to the character build up at the front, this needed a better arc of closure. My favourite part was the middle when they were in Scotland. Quite dramatic. The touch of Iceland of Ridpath was just icing on cake. Fun commuter series.
Profile Image for Anne G. Kasaba.
1,923 reviews9 followers
March 14, 2018
I’ve never read a book by Mark Dawson that I didn’t like and this one is no exception. A page turning storyline that keeps your heart pumping, and strong characters keep you reading well into the wee hours.

Hedge funds need people with strong nerves and good instincts. But power can corrupt and those strong nerves can lead to murder. Add in a two professional killers and an angry big brother and there’s no telling who will die.

I received an arc of this book and voluntarily provided a review.
1,910 reviews7 followers
March 14, 2018
I loved the new hero in this story, Bjorn Thorsson. An Icelandic giant, physically and mentally tough but with his own demons - what's not to like? He will do whatever it takes to protect his little sister and falls onto Group 15's radar. As always, the story is enthralling, fast and furious and action packed from start to finish. Here's hoping that Mark decides to write more stories involving Bjorn.
These novellas are a very welcome addition to the Group 15 canon and keep me going until I get my next Milton fix.
Profile Image for Sue Morris.
82 reviews
March 16, 2018
A little disappointing

I am a massive Mark Dawson fan but this novella didn't seem to be of his usual excellent standard - the plot or writing style. It may be that I'm not a big fan of novellas. However I suspect cause maybe more to do with Mark 's co-worker Michael Ridpath. Based on this book alone I would not rush to read any other book by Mark Dawson. If this is you first read of his work, please don't be put off reading his other books, as they are great. Mark Dawson please go back to writing on your own and full novels if possible!
Profile Image for Chris.
583 reviews47 followers
March 21, 2018
Enjoy these books with other authors

I have read and enjoyed everything Mark Dawson has written. The espionage thriller storylines suit me and are well written and edited. No typos or grammatical errors in these independently published books. I appreciate that greatly. The author also interacts with readers on facebook which I enjoy. I especially enjoy these short novels written by with other authors. I like how each feels different because of the input from the guest authors. Great series and fun getting more information about Group 15 in this one.
582 reviews
March 13, 2018
Another novella from Group 15's more recent past. We get a better look at how the Group works, from giving out assignments to recruiting new operatives. Guilt over a dead sister changes Bjorn life in a major way. As Bjorn seeks his revenge, he finds himself in the crosshairs of Group 15. Blood and death results. Very enjoyable story, with an appearance of one of my favorite character, Pope. Looking forward to more tales from Group 15.
80 reviews3 followers
March 28, 2018
It left me hanging

and wanting more!!!! I hate when the book leaves you hanging but in this case I’ll cut the author some flack. If you haven’t tried any of Mark Dawson’s novels/ novellas give them a try. You won’t be disappointed. Great characters and plenty of action. John Milton, Isabella Rose and Beatrix Rose among others will all become memorable characters making you beg for more.
Profile Image for Darlene.
502 reviews26 followers
April 11, 2018
Little Sister

Out of all the Group Fifteen books, I think this was my least favorite. Not that it wasn't good, it had its moments. But, the beginning was slow and it seemed I kept wondering when the Group was going to get involved. It seemed to focus on other characters more heavily than leaning more about Group Fifteen. All and all it was a decent read if you can get past the beginning and into the guts of the story.
Profile Image for Trish R..
1,772 reviews58 followers
April 29, 2018

This was completely different from the other novellas. This was about Bjorn who was out to kill a man but Bjorn had nothing to do with Group Fifteen until the last 2 or 3 pages of the book when Pope showed up to offer him a job.

There was nothing exciting about this story until the last 15 or so pages. It was okay but not nearly as good as the other two novellas.

Also, this was not on audio so I just read it and that was okay, too.
1,477 reviews25 followers
May 19, 2018
Little Sister. Mark Dawson

Bjorns sister is in a relationship with an extremely unscrupulous business man who is being blackmailed by an ex employee. The solution is simple, murder. Bjorns sister knows and confronts him. She is killed in what appears to be a brazen murder by a junkie. Bjorn knows what actually occurred. The rich boyfriend will die. His sister's death will be avenged Fast paced action thriller. Enjoyed immensely!
Profile Image for Sam.
258 reviews5 followers
January 31, 2021
This novella about Group Fifteen, post-John Milton and pre-Isabella Rose. The novella features assassins, both private and state-sponsored, with two American businessmen at the center of corrupt business deals that also includes murder. This fast pace novella deserves more pages. I say this every time, Netflix or Amazon Prime need to purchase the movie or TV rights to Mark Dawson’s novels. They would make a great series! I continue to enjoy his books.
Profile Image for Jim A.
1,267 reviews82 followers
March 13, 2018
Once again I was fortunate enough to be able to read an ARC of one of the Group 15 stories.

Former SAS drawn into revenge after the murder of his sister by an oligarch.

As with the other Group 15 stories, this one is co written with Dawson, giving an opportunity to enjoy another author's talents as well as Dawson's.
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