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DCI Kett #10

Knock Knock

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THE TENTH INSTALMENT IN THE INTERNATIONALLY BESTSELLING DETECTIVE MYSTERY SERIES!

Whatever you do, don’t open the door… When a severed foot is delivered to the unsuspecting residents of a student house in Norwich, DCI Kett’s Extreme Crime Task Force begins one of the most gruesome investigations of its career. And it’s not just a foot. More packages begin to appear at random on people’s doorsteps, all of them containing body parts that have been surgically removed and meticulously wrapped. Kett, Porter, Savage and PC Duke find themselves in a race against the clock to identify the victims and their killer, who shows no sign of stopping. Because it soon becomes clear that this monster isn’t just delivering corpses.

He's delivering a message...

Relentless action, compulsive mystery and dark humour abound in the internationally bestselling series that Thrilling Fiction calls "Heart-stoppingly gripping!" from the million-selling author that James Patterson describes as "fresh and ferocious!"

Binge the series
PAPER GIRLS
BAD DOG
THREE LITTLE PIGS
WHIP CRACK
RUN RABBIT RUN
STONE COLD DEAD
EVERY MOTHER'S SON
SWEET BRIAR ROSE
JAW BREAKER
KNOCK KNOCK
KING RAT

Alex Smith wrote his first book when he was six. It wasn’t particularly good, but it did have some supernatural monsters in it. His latest books, the DCI Robert Kett thrillers, have monsters in it too, although these monsters are very human, and all the more terrifying for it. In between these two books he has published thirteen other novels for children and teenagers under his full name, Alexander Gordon Smith—including the number one bestselling series Escape From Furnace, which is loved by millions of readers worldwide and which is soon to become a motion picture. He lives in Norwich with his wife and three young daughters.

480 pages, Paperback

First published June 30, 2022

1159 people are currently reading
436 people want to read

About the author

Alex Smith

25 books679 followers
Alex Smith wrote his first book when he was six. It wasn’t particularly good, but it did have some supernatural monsters in it. His latest books, the DCI Robert Kett thrillers, have monsters in them too, although these monsters are very human, and all the more terrifying for it. In between these two books he has published twelve other novels for children and teenagers under his full name, Alexander Gordon Smith—including the number one bestselling series Escape From Furnace, which is loved by millions of readers worldwide and which is soon to become a motion picture. He lives in Norwich with his wife and three young daughters.

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5 stars
3,418 (66%)
4 stars
1,303 (25%)
3 stars
321 (6%)
2 stars
45 (<1%)
1 star
26 (<1%)
Displaying 1 - 30 of 138 reviews
1,727 reviews110 followers
November 7, 2024
Another fantastic book in this series. This one left you on a cliff hanger so, it won't be too long before I start the next one.
Profile Image for Steven R. McEvoy.
3,798 reviews172 followers
August 30, 2022
I had pre-ordered the eBook for this, so it dropped to my devices on release day. But when it released I was busy at work and in some other series of books, and it sort of fell off the radar until my manager at work, whom I introduced Kett to, mentioned his physical copy had arrived. I went and bumped the ebook back to the top of my reading list. It is by far the longest book in the series to date. Listed as 478 pages. Each book in the series had gotten longer and I can only wonder if the next volume will surpass 500 pages. I devoured this volume over 3 days. It was hard to put down. Now it was not as fast paced as some of the other Kett novels. And really not as violent or gruesome. But the last section man what a set up for book 11, Rat King. The description of this instalment in the Kett saga is:

“Whatever you do, don’t open the door…

When a severed foot is delivered to the unsuspecting residents of a student house in Norwich, DCI Kett’s Extreme Crime Task Force begins one of the most gruesome investigations of its career.

And it’s not just a foot. More packages begin to appear at random on people’s doorsteps, all of them containing body parts that have been surgically removed and meticulously wrapped.

Kett, Porter, Savage and PC Duke find themselves in a race against the clock to identify the victims and their killer, who shows no sign of stopping.

And it soon becomes clear that this monster isn’t just delivering corpses.

He's sending a message.”

I started this book the day it released, and even though it was a very busy week at work I ripped through it in a few days. I could not put it down. All of the Kett books are dark, and somewhat disturbing British Crime Thrillers, but this one takes it to a completely different level. Kett and his new team the Norfolk Constabulary’s Extreme Crime Task Force, have gone on holiday for some team building time. But the few days away do not end up relaxing in any way shape or form. It is another great story an intense series. There are a few twists in this tale and somethings very much unexpected.

If you have been fallowing the saga of DCI Kett this book is a must read. If you happen to be a fan of rough and tough action you will almost certainly enjoy this novel. And the other books in the series. This is the eleventh of the DCI Kett stories that I have read, the tenth novel, Kett has also made a brief appearance in The Harder They Fall, the first of the Softley Series of books. But back to this volume.

This one is much more of a procedural crime thriller. Kett and the team are working a case where couriers are delivering body parts. They soon find out it has ties to a much larger problem. And that there are different forces at work her. When you include a rowdy football team, and it’s star player. Said star being the son of a former MP and mouthpiece for the Alt Right. But when a second appendage shows up it at first seems completely unrelated. And then … but that is getting aHEAD of the story. The return of Norman Balls sheds some light in dark places the police were unaware of. And using skill, cunning and just a bit of luck Kett and the team have a chance to stop a madman. But Can they put it all together in time? To Find out you will need to read this story. With over 2600 reviews on amazon and 1350 on Goodreads this story average s 4.5 stars.

This is another dark and gritty crime thriller from the pen of Alex Smith. About the author we are informed that:

“Alex Smith wrote his first book when he was six. It wasn’t particularly good, but it did have some supernatural monsters in it. His latest books, the DCI Robert Kett thrillers, have monsters in it too, although these monsters are very human, and all the more terrifying for it. In between these two books he has published thirteen other novels for children and teenagers under his full name, Alexander Gordon Smith—including the number one bestselling series Escape From Furnace, which is loved by millions of readers worldwide and which is soon to become a motion picture. He lives in Norwich with his wife and three young daughters.”

My introduction to Smith’s works were The Furnace novels many years ago. I have not read everything he has published but much of it. And they are always edge of your seat thrillers. I still hope that someday he will finally release book 2 is the Softley Softley Series, but until then I am thankful for another read in this dark and disturbing series. For some the Kett stories will be the things of nightmares, for others a look at the underside of society. But no matter how you read them they are crime thrillers with a lot of action, great characters and often a lot of violence!
Profile Image for Anastasia.
2,268 reviews102 followers
September 12, 2025
Knock Knock by Alex Smith is the 10th book in the DCI Kett series. The Extreme Crime Task Force is sent to investigate a severed foot sent to a student house in Norwich, setting them off on a hunt for a killer as more packages of body parts are delivered. An incredible twisted thriller showing how the dark web can be used as cover for crimes. There are some particularly nasty entitled characters. We are left with a cliffhanger leading us onto the next book, just as Kett and his family have purchased a new house hoping to leave the past behind but it seems it will never leave them. A superb, unputdownable and gripping, suspense filled thriller.
Profile Image for Patsy.
713 reviews21 followers
June 26, 2024
I do enjoy this series and the characters but the plot lines are getting more and more improbable with each book.
12 reviews
July 3, 2022
wow wow wow !!!!

I didn’t even know this was out !!! and I just clicked on my email and saw a message saying it was available!!! I have read the book in a couple of hours !! Children, housework, animals, garden, anything has gone to pot as apparently I growled at them when they came near me !!! I don’t know whether I love you or hate you Alex smith ??? I literally devoured this book !!! And I am waiting with bated breath for the next one !! So don’t leave me too long !! X
Profile Image for Kirsty.
48 reviews1 follower
January 8, 2023
Knock Knock is easily my favourite of the DCI Kett series.

And left the way it was……you can’t not read the next!
Profile Image for Joe’s Mum.
40 reviews16 followers
July 9, 2022
Another great Kett story but I’m now looking forward to Book No 12, because I doubt I’ll be reading Book No 11. I was so disappointed with the last chapter, that storyline should be over by now and for a man who gets out of every single ‘scrape’ he gets himself in, the ending just didn’t make any sense, walking out of the house and down the street, where cars with sinister occupants had been seen, with a colleague who had cleared his desk out earlier in the day with no explanation. Plus I think I read a similar book not long ago where a colleague did the same thing - let’s hope there is no spin off series for this one.
I love Kett (probably my favourite policeman) and his work colleagues, love Billie and the girls are a laugh a second but I nearly threw the book across the room with the Hollenbeck ending.
I understand all the 5 star reviews but not from me this time.
This entire review has been hidden because of spoilers.
Profile Image for Carly Rushforth.
583 reviews28 followers
March 30, 2023
OMG what a cliffhanger this book ended on! I’d planned to read another book after but I can’t 😨😳
I need to read book 11 asap!

I’d you’ve read it you’ll know what I mean 😵
5 reviews1 follower
November 15, 2023
Alex Smith’s Robbie Kett novels are always fast paced with surprising endings. I have read all of the preceding books and enjoyed them!!
Profile Image for The Book Review Café.
870 reviews238 followers
July 28, 2023
This is the tenth instalment in the DCI Kett series, and it’s one of those rare crime series that never fails to deliver.
Relentless action, compulsive mystery, dark humour with gory crimes, this is an author who knows how to keep the crime thriller reader throughly entertained. Alex Smith has a very devious mind, teasing with red herrings, and fake conclusions. I love Kett, his crazy family and his team, their banter adds a dash of much needed humour to his dark plots. I think Knock Knock is the darkest one yet and it was great to finally get some answers around the sinister group targeting Kett.



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Profile Image for Toni H .
891 reviews2 followers
January 6, 2025
A college student receives a package in the mail and when she opens it, the package contains a human foot. DCI Kett and the team are assigned to the case. Then other packages start being delivered to other residents containing other body parts, the team realizes they are under pressure to catch the killer. They first have to discover what all the residents who received the packages have in common. Once they find the common link, they discover something more sinister. The killer is sending a message and they have to stop him.
Profile Image for Leah.
43 reviews2 followers
November 25, 2025
I think this one might be my favourite yet! The plot of this was really good, and it seemed so straight forward at first! However, like all Alex Smith books, it quickly became clear this was not the case!
The ending of this book shocked me too! Hollenbeck has always been lurking in the background of all the books, however the twist with DCI Dunst - I really didn't see that coming. Never started another book in a series so quick!
53 reviews
November 20, 2022
So glad there’s only one book left in the series because my nerves are in BITS! Haha! For goodness sake, I can hardly cope. Let’s get this over and done with and please Lord don’t let there be a cliffhanger!!!
24 reviews
April 29, 2024
Wow, these books are really making you think of the different monsters there are in our streets.
This book did keep you guessing, trying to find the connections!
Another enjoy part of the DCI Kerr collection. I’m not bored of them yet so in to book 11!
92 reviews2 followers
July 28, 2022
Excellent writing as always

i really enjoy the interactions of his regular characters. Yet author's complex stories have begun to try to reach new heights of evil. This is a very good writer, as seen in earlier novels, such as Paper Girls. Yet he seems to keep reaching further and further afield to bring more grotesque characters and stories, in ever more improbable situations for our battered central character.

Probably will no longer follow.
2 reviews
August 24, 2022
I ‘m a considerable fan of the Kett books but was disappointed by the latest offering. The plotting seemed weaker than in previous novels and both the general milieu and the interaction between the characters seemed off with Clare in particular reduced to an almost buffoonish caricature and a shift in the relationship between Kett and Porter which felt completely unnatural. I’ve always disliked the parts of each book devoted to Kett’s children who are presumably intended to be annoying but endearing ( but only have the former effect on me ) but I alway adopted ‘a grin and bear it’ attitude since there was so much else to enjoy. This whoever was much less the case this time and the failure to resolve the issue of the sinister football coach but hastily making reference to him being taken in for questioning felt massively unsatisfying. I will, of course, be reading the next one as soon as it appears while fervently hoping it’s a return to form and that Knock Knock was just a bit of a blip..
303 reviews1 follower
July 8, 2022
That ending though!

Ok Alex Smith! You didn't have to end the book that way, I would be reading number 11 anyway! What a book, it was everything I love about this author. An intense plot, that is very original! Enough twists and turns to male you car sick!.and there's comedic relief! So much of it there were many times I was laughing out loud. As long as this book is (over 400 pages), I never felt that the story was dragging along. Every bit of it was a compelling read. I just didn't want to stop! And too be honest, the only reason I did stop was because I fell asleep in my chair at 1am. This book can be read as a stand alone, but you wouldn't understand much of the past that was talked about. And you'd never understand the ending. I do suggest you start with book 1, no question, this is an amazing series! Don't be the one that misses out!
Profile Image for Sarah Clark.
37 reviews
July 18, 2022
I was not expecting that! How on earth do these books keep getting better and better! A fantastic read, I was howling in places. I cannot wait for King Rat!


Whatever you do, don’t open the door…

When a severed foot is delivered to the unsuspecting residents of a student house in Norwich, DCI Kett’s Extreme Crime Task Force begins one of the most gruesome investigations of its career.

And it’s not just a foot. More packages begin to appear at random on people’s doorsteps, all of them containing body parts that have been surgically removed and meticulously wrapped.

Kett, Porter, Savage and PC Duke find themselves in a race against the clock to identify the victims and their killer, who shows no sign of stopping.

And it soon becomes clear that this monster isn’t just delivering corpses.

He's sending a message.
Profile Image for Mr Mark Hawksford.
352 reviews6 followers
July 23, 2022
Knock Knock -

I can easily say that the Kett series are my favourite set of books. All of the books in the series are crackers and I keep asking myself, will the next be as good? This was. As usual, full of action, great humour, lovable characters (that’s Kett and the team - not the people he’s going after) and I just find them so easy to read. Some books you read but find it a struggle. You just don’t want to put these books down. I’ll not say anything other than the book gets even better on the final two pages. I can’t wait for the 11th book - King Rat - roll on 1st November. Alex - thank you for a great set of books. Can I give it 6 out of 5 for the whole series.
Totally recommend anybody who hasn’t read any of the Kett series starts at number 1 and works there way through to 10.
152 reviews2 followers
August 11, 2022
Intense Twist of Murder and Mayhem

Alex Smith writes with such a wonderful style. His characters are richly written, devoted to each other. Dark humor keeps them coping and quirky new members are introduced throughout the series like Norman Balls. The internet conspiracy theorist who is a 30 something man child who lives with his Mother. I recommend you start with book one of the series. Very entertaining if you like real life horror stories.

Dark times for the Detectives, who are working thru multiple rare amputation events. Evil knocks loud. Body parts are being delivered throughout the area. Is it murder or are the victims alive? Clues are found but also taking chances reveal the true nature of crimes. This is a 5 star fast paced book.
285 reviews3 followers
May 28, 2025
WOW, that was an amazing read, what a book!

I literally couldn't put Knock Knock down and I couldn't read it fast enough. I was on the edge of my seat from start to finish and even though the story was pretty gruesome I still found myself laughing out loud, usually at Clare and Duke's expense, the nose hair references were just too funny 😂

The story was brilliant and kept me entertained and engaged from those first pages until the very last. Even though it's got more pages, it didn't feel any longer than the other books because you're getting carried away by the momentum of the fast paced story line.

I totally recommend these DCI Kett books, you won't be disappointed, lots of crime, action, murder and humour too. If that's what you're looking for?
Profile Image for David Ward.
Author 2 books17 followers
November 3, 2022
DCI Kett and the Extreme Crime Unit struggle again against huge odds but come out on top - I think.

The trouble is, I'm not sure if they did or not. Knock Knock ends by drawing the reader straight into King Rat, newly published in November 2022. Alex Smith has a habit of doing this to his readers, and I for one like it. If King Rat ends the same way there'll be a fair wait before DCI Kett #12 is published.

Knock Knock is pretty grizzly, it has to be said. The evil character who is the main antagonist is unexpected and very, very nasty. I can say no more without giving things away.

A good book, especially if you like crimes with a bit of blood and guts.
Profile Image for Mary Johnson.
1,032 reviews17 followers
November 16, 2022
These stories are good but each becomes more and more complicated. Some of the characters are well developed but others remain two dimensional. A senior officer who barks all the time using the same (wrongly understood) risqué word does not compensate for a lack of background. Finally, I a lead character is just that. He doesn’t have to constantly be in the thick of it with bits of him being sacrificed or pummelled. He could ‘share the glory.’ With others. Finally, the vicious murderer snd his disciples coming after him in every book….. I like a work of fiction but for goodness sake , can it be balanced with some realism.
522 reviews3 followers
February 28, 2023
Excellent read.

Wow!
Best book of the series.
Exceeded expectations by a long way.
Deliveries of body parts, cryptic clues, a Dark Web assassin and the worm who turned.
Moat surprising of all was a major break in the case came from local historian / web junkie / general pest and would be detective, Norman Balls. He finally hit pay dirt with his excursions into the Dark Web with his fellow civilian investigators.
Couldn't put this one down, apart from bathroom breaks.
The same fast pace as the first few books in this series, no slouching in this one. So
Alex Smith & DCI Kett are both back on form and raring to go.
64 reviews
July 28, 2022
Another great book.

I chose to rate this book with 5 stars because I couldn't put it down. I love this character, it's non stop from the first page. Poor old Robbie seems to get battered every time but still gets up. These books are always exciting, expressive and totally engrossing. Alex is such a good writer that brings his characters to so much life. I would tell anyone who likes crime stories to seriously read these books, right from the start if you haven't read them. I'm on to the next one.
110 reviews2 followers
October 5, 2022
Knock Knock

Omg what a cliff hanger to the end of this book. I think this was the best one yet although the rest have been amazing reads. I can't wait to get into the next one. The dynamics of the team have come together so well they are like a little family each one bringing something different to the investigations . The storylines are so good. Fast paced and impossible to put down. My favourite kind of read. I thoroughly recommend this series of books you won't be disappointed.
Profile Image for Teresa Perrott.
151 reviews1 follower
October 21, 2022
Definitely edge of threat again. Just when everything seems to be going ok for Robbie and Billie right at the end there is another turncoat. Before all that though people are receiving interesting packages, but all is not as it seems. Things have been set in motion in the first place for those packages to arrive how they do. Robbie, Porter, Clare, Savage and Duke are after a hidden person, who is hiding in plain sight. Can not wait for 1st of November 2022, I just home Robbie and Billie get that happiness.
This entire review has been hidden because of spoilers.
Profile Image for Janet C. Simpson.
20 reviews1 follower
August 1, 2024
An excellent author who really had me on the edge of my seat at times, although having read several of his books by now DCI Kett is becoming predictable. I almost didn’t continue after the first book in the series because of Kett’s horribly spoiled children but I now tend to skim over those bits and get to the meat of the story. Reading the author’s bio I see he has three daughters whom I assume he is basing Kett’s daughters on, I just wish they weren’t included in the story as much as they are.
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