Jump to ratings and reviews
Rate this book

Warhammer 40,000

Belisarius Cawl: The Great Work

Rate this book
An Adeptus Mechanicus novel

In the wake of the Great Rift, Belisarius Cawl turns his attention to the abandoned world of Sotha. Once home to the Scythes of the Emperor, it also hides a long-buried secret… and an ancient evil.

READ IT BECAUSE
Cawl is one of the most fascinating characters in the Dark Imperium, and Guy Haley gets right into his memory circuits as he seeks ancient secrets that will blow your mind.

THE STORY
Belisarius Cawl, Archmagos Dominus of the Adeptus Mechanicus is the most brilliant mind alive. For 10,000 years he has furthered the cause of mankind, working under the aegis of the Emperor and Lord Commander Roboute Guilliman to prevent the inexorable march of the alien and the traitor. Many call him heretic, but all must recognise the magnitude of his achievements, for who else but he was entrusted to create a new generation of Space Marines? Who else but the great Belisarius Cawl could even accomplish such a task?

Now, in the wake of the Great Rift and the Indomitus Crusade, his ambitions bring him to the long-dead world of Sotha, once home to the Scythes of the Emperor, now a barren wasteland devoured by the vile Tyranids. Accompanied by Tetrarch Felix and his elite warriors, it is here that Cawl believes the lynchpin of his mysterious Great Work lies. But uncovering it is a near impossible task, one in which the Archmagos must overcome an ancient evil that threatens to extinguish the last hope of humanity.

416 pages, Paperback

First published September 21, 2019

223 people are currently reading
1205 people want to read

About the author

Guy Haley

282 books697 followers
Guy Haley is the author of over 50 novels and novellas. His original fiction includes Crash, Champion of Mars, and the Richards and Klein, Dreaming Cities, and the Gates of the World series (as K M McKinley). However, he is best known as a prolific contributor to Games Workshop's Black Library imprint, and has sold over 2 million books set in their Warhammer universes.

Ratings & Reviews

What do you think?
Rate this book

Friends & Following

Create a free account to discover what your friends think of this book!

Community Reviews

5 stars
922 (42%)
4 stars
898 (41%)
3 stars
299 (13%)
2 stars
48 (2%)
1 star
6 (<1%)
Displaying 1 - 30 of 162 reviews
Profile Image for Michael Dodd.
987 reviews79 followers
December 10, 2023
On the dead world of Sotha, Cawl meets with Tetrach Felix of the Ultramarines and Chapter Master Thracian of the Scythes to uncover the secrets of the Pharos, searching for knowledge amidst the ruins of the Scythes’ homeworld. Between Cawl’s apparently reckless pursuit of information and Thracian’s secretive motive for being there, Felix has a hard time keeping the mission on track and ensuring the safety of all parties as the dead world proves to still contain considerable dangers.

Never one to take the easy option, Haley draws together threads from his Dark Imperium series and his Horus Heresy novels Pharos and Wolfsbane, plus the Scythes of the Emperor arc created by Richard Williams and LJ Goulding, cleverly bridging the Heresy, pre-Dark Imperium 40k and the ‘current’ timeline. Whether you’re after an action-packed sci-fi adventure, a lore-rich continuation of the current 40k setting or an insightful exploration of some fascinating (and potentially divisive) characters, this should have something for you. It's a pacy, compelling read in its own right while balancing multiple existing story arcs in a cleverly constructed narrative packed full of creativity and character; put simply, if you like 40k then this should be on your list of books to read.

Read the full review at https://www.trackofwords.com/2019/09/...
Profile Image for Sud666.
2,308 reviews194 followers
March 6, 2021
That was surprisingly good. The story starts off a wee bit disjointed since it jumps around a lot, in terms of time. But, in the end, it is a great addition to the Black Library.

Belisarius Cawl, Archmagos of the Adeptus Mechanicus, is a genius. Working hand in hand with the Emperor, he is responsible for helping to find archeotech and STCs, as well as the Primaris project. He is a huge figure in the 40K universe. This tells his story.

What a story it is. From the "formation" of Cawl, to his work with the Emperor, as well as some fascinating tidbits about WHOM Cawl truly is- this entire story was a pleasure and it fills in a lot of "lore holes".

While this is a "history" of Cawl, it also tells the tale of the finding of the Pharos beacon. Cawl's personality and intellect, make him a very cool character. This book tells, in essence, three stories. The first is the story of Cawl, all 10K years of it. The second has to do with the activation of the Pharos and the conflict with the C'tan. The final story has to do with the dark secret of the Scythes of the Emperor and the fall of their homeworld to the Tyrannids.

These three stories make for a great book. The little bits where Cawl interacts with the Emperor is truly fascinating. As is the driving impetus for Cawl's visions. An entertaining and informative book. Highly recommended for 40K fans.
Profile Image for Skywatcher Adept.
49 reviews2 followers
September 22, 2019
There are more reveals in this book than all other 40k publications in 2019 (including Horus Heresy) coupled together. Overwhelming amount of events placed along circa 11 000 years of 40k Universe.
Profile Image for Danie Ware.
Author 57 books205 followers
January 23, 2020
Shorted from five stars only because my own mythological knowledge doesn’t quite keep up, but a truly wonderful read nonetheless. Take Aliens, and explode the plot to deification levels. Throw in equal parts science, quantum physics and a bit of old school magick, set it to the songs of gunfire and humming servo-motors, and weave it through with Cawl himself - from his earliest beginnings to his ongoing chuckling arrogance to his masterwork. A character of legend, and done full justice!
Profile Image for Arvid Kongstad.
24 reviews
August 9, 2020
My favourite 40k novel so far. Sure, it is an action novel set in a universe that knows little other than war, but the story and dialogue is very well-written and there were some really cool passages. I was surprised how much I like the character of Belisarius Cawl and I think this book provides some useful background to current developments in the 40k universe, like the Indomitus Crusade.
Profile Image for Bookcat.
2,206 reviews4 followers
January 17, 2024
Belisarius is so...human, for one of the Mechanicus. Wish there was a clearer alert between the story's time jumps. I got a little lost between past and present a few times. Anyway, really liked this, so fascinating and a little funny (to me) because, "How dare you kill my friend!" Then *BLAM!* takes her head off 🤣
Profile Image for Matias.
76 reviews3 followers
September 25, 2020
Oh Cawl. The Gary Stue of 40K. You just have to ruin Pharos here as well, don't ya?! I'll still give 4 out of 5 stars for this. So why is that?

Short:
I recommend this as a necessity for any 40K fan. A necessity that is not bad at all; in fact, the opposite. For newcomers, I'd say leave this for a bit later; much later even.

Longer "review" (rant?):
So yes, noting on some non-review side of things, Cawl is THE unexplained OP character whose only reason was to make money by creating another set of Space Marine miniatures to sell. Nice work Games Workshop. This will be an impossible task for the writers to create anything even averagely good lore material. Good thing our novel writers are at least somewhat up for the task.

As a long-time ('ish) fan of the 40K franchise, this was almost a "lorebase-politically fanbase confronting" novel (kind of mouthful that one). And damn you Mr. Guy Haley. You just HAD TO write an interesting story even from this one as well. Not kidding here fellas, this is for real. Couldn't find boring characters here... Well I guess the Primaris are acting like naive little... little things... But they are what they are because of actual lore reasons.

Well my next 40K novel read won't be from you Mr. Haley. Oh wait, I think it is.
Profile Image for Jordan.
8 reviews
December 25, 2024
I was pleasantly surprised by this book! Normally, the amount of jumping back and forth in time (from multiple characters' perspectives) would be confusing to follow. Thankfully, it's written well enough that the time jumps are easy to keep track of.

Belisarius Cawl is a "know-it-all" in the best way, his smug enjoyment when his plans succeed is fun to read, very much a "See? There is nothing to worry about." Attitude while doing something incredibly dangerous (and heretical maybe). I won’t dive into spoiler territory, as I’d end up writing an essay. The combat scenes are well written, and Belisarius Cawl is done justice as a character. I also really enjoyed the Primaris Marines characters and their history/backstory, as well as Cawl's own backstory. The pacing feels good, 400+ pages gives it a lot of room to breathe.

Overall, I would recommend this book if you're looking for something to add to your 40k library.
Profile Image for Fiona.
308 reviews8 followers
June 8, 2023
Fascinating and extraordinary, this story reveals a lot about the fabled Belisarius Cawl.

And still, the history of that shady character is only the remarkable side dish of an incredible Space Marine mission, facing off against the most exotic of aliens: Invasive Tyranids, ancient Necrons and more.

If you enjoy lore-monging as much as I do, than this is a must read. I think most of the narration was story and progress-making into the so called Pharos, after Sotha's entire biomass and atmosphere had been devoured by Swarm Kraken. We get a peek into the making of the innovative Primaris Space Marines while we see the consequences of "The Scythes of the Emperor"'s unmaking.

But the enemies are illusive today, and the battles are often fought with light and shadow more than flesh and ceramite. So don't expect too many direct stand offs, but more unexpected tactics and methods of 40k warfare.
Profile Image for Amara Sunflowers.
8 reviews
January 7, 2022
Really loved this read I've liked the 40k universe for a while and got into a lot of lore videos online many of which suggest reading the books and they were correct. Guy Hayley blew me away with constant twist and turns in this white knuckle ride. Belisarius Cawl is a tech priest who is conceals much from his compatriots and even himself being alive for over a century there is more in the data banks of his mind than he could ever keep track of. As such it comes to a head with him battling some of humanity's most feared foes and faces more than one god.

An absolute page turner.
Profile Image for Mitchell.
117 reviews1 follower
June 18, 2022
Guy Haley stikes again with another cracking 40K biographical novel after the brilliant Dante biography.

This time it follows Belisarius Cawl and his origins. Told via an equally interesting Space Marine focused subplot, the novel has the right balance between quiet character building moments and action (a rarity in 40k novels at times).

Highly recommend for any 40k/Space Marine/AdMech fans as a great starting point into the 40k lore.
6 reviews2 followers
July 8, 2020
Very well written, especially when it comes to the characters. One of Warhammer 40k's character driven master pieces.

Every chapter draws you in to the dynamics that Guy Haley has woven. There are some enjoyable hints of 40k mysticism and history throughout.

Side point: There is a particular point connected to 20th century fairy tales and science which is amazingly done well.
Profile Image for Mitchell George.
86 reviews
February 28, 2022
Fantastic study of the brilliant character of Belisarius Cawl. It struggles in the first half, especially in the modern day stuff, and the Scythes of The Emperor plot line really feels a bit tacked on, but the exploration of Cawl and Felix's backstories, and the true threat they're facing is nothing short of brilliant. Very recommended reading, especially for those intrigued by the character in Dark Imperium.
Profile Image for John.
9 reviews
February 20, 2023
A good read! Starts out a bit weird with all of the jumping about, but tells a great story of a mountain journey and a story of friends made along the way or something like that?
Profile Image for R. Jones.
381 reviews5 followers
January 17, 2024
Lore, action, multiple factions, plot progression, and an interesting main character. Pretty much everything you might want from a WH40k book.
Profile Image for Miles Taylor.
22 reviews
August 13, 2025
Belisarius Cawl is becoming one of my favorite characters. I found this story pretty schweet!
Profile Image for Isaias McAllus.
172 reviews6 followers
July 18, 2023
Me ha encantado. Belisarius Cawl es el mejor personaje del Imperio y uno de los mejores de todo Warhammer 40k
Profile Image for Nicolas.
36 reviews
May 22, 2024
I liked the character of cawl how his many lives affected his brain and his memory, I find that one thing I didn't like is that though its supposed to be an admech book there is still a lot of space marine in it.
Profile Image for Reader.
22 reviews
June 10, 2025
Belisarius Cawl The Great Work by Guy Haley.
Straight away I will tell you I'm not sure what to make of this book. It's not bad, it's still a decent read but for me it felt like someone had a great idea for a book but couldn't make it stretch to a full novel so had to add in another short story.
The story is set around the planet of Sotha which is the home of the space marine chapter " The Emperors Scythes". They are accompanied by Felix the newly appointed tetrarch of this section of ultramar as they attempt to reclaim their chapter monastery after a tyranid invasion.
They are joined by Belisarius Cawl the archmagos of the mechanicum as they try to work out what happened.
Upon arrival it is clear not all is well as various members start having vivid flashbacks and Cawls suspicions are confirmed that there is more going on within the mountain than is first apparent.
The story sort of splits with half being what cawl is trying to do and half what the emperors scythes are trying to do.
The Scythes are led by their chapter master Thracian as they try to cover up/make right a secret within the chapter, I don't know if its because I've read alot of warhammer by now or what but I wasn't exactly blown away by the reveal of "the secret" and not to be a misery I didn't really care by the end.
The star of this story is Belisarius Cawl and we learn alot about his past and his goals for the Imperium of man. He is a really engaging character and is genuinely funny. His interactions with Felix and Primus are really engaging and his part of the book is very entertaining.
I found Felix a bit annoying towards the end as he became that character in a movie that just refuses to do what he's been asked to and as I've already said i wasn't really bothered about the side quest.
This book feels like it could have just been like the book "Valdor" which is quite short and very focused on one character rather than have a rather unnecessary add on.
I enjoyed the Cawl parts very much and if you're interested in the character its worth a read just try to breeze through the other bits.
The next book I'm reading is "Siege of Vraks" by Steve Lyons
Profile Image for Alasdair.
105 reviews2 followers
January 11, 2020
A fairly solid entry into the post Dark Imperium timeline.
Profile Image for Swords & Spectres.
433 reviews19 followers
January 1, 2024
This is the origin story of Belisarius Cawl, one of the more important members of the Adeptus Mechanicus. It shows you his beginnings and many of the great works he's had a hand in during his lengthy life. Despite my low rating, I do feel for the purists out there who want to get all they can from the lore of the 40k universe, it's an important read.

I, however, am more of a casual reader of the franchise (I doubt I'll ever truly get my hooks back in to the extent teenage me did, but that's their fault for killing off my favourite fantasy world ... but I digress). That being said, for the casual reader, it is A LOT to take in. And it isn't presented in a way that is easy to take in. Maybe it's easier to read physically than it was via audio book, but I found the relentless time skips incredibly jarring on the pacing of the novel. Speaking of jarring, the use of the word 'BANG' whenever the author wanted to skip times felt amateurish at best and incredibly annoying at worst. Surely there are better ways ... like just go with the 'Circa ten thousand years ago' sub-heading it used anyway?

I also felt that, for a novel where the characters were very two-dimensional, there was an awful lot going on. Due to the characters only being fleshed out to a certain degree, I never felt myself caring too much for what was happening to them. They were sad? I felt nothing. They were in danger of being overrun and killed? My heart wasn't pounding like it should have been.

My overall feeling on this was that it had a lot of cool insight into the Imperium's past and such things as the Primaris Marines, but it felt so dry and unexciting to me. If I find myself needing to refresh my knowledge on Cawl's lore, I think I'll just read the wiki entry
Profile Image for PJ.
24 reviews
January 6, 2021
Good - Fleshes out Cawl as a character, and continues to build on Felix. Has some interesting implications spread throughout.

Bad - Pacing, particularly the first 2/3rds of the book and most of the ‘modern’ day sections which seem to drag on. Contain a plethora of ‘named characters’ who blur in to one and are frankly interchangeable.
Profile Image for Christopher Napier.
92 reviews
July 9, 2020
Decent 40k book delving into the backstory of Archmagos Cawl as well as a current operation featuring the Tyranid ruined homework of the Scythes of the Emperor and some interesting developments in the delving beneath their former fortress monastery.

This story feels like it should be huge, dealing with things millenia (and longer) in gestation, adding to characters and locations as significant as Cawl, the Pharos and the fate of a whole chapter.

It doesn't quite land, partly because of the time skipping used as part of the narrative and the fact that we don't really care about anyone but Cawl and even then its because he's such an egotistical price.

On the surface this story has everything, Space Marines facing a variety of xenos threats, story hooks going back from before the Horus Heresy and impacting on the current setting and genuinely world shaking final confrontations.

It just feels all a bit... Michael Bay, if that makes sense. Awesome set pieces but how we get between them is spotty and caring about the characters is a secondary element.
Profile Image for Joel Harris.
Author 1 book14 followers
Read
December 27, 2019
Brilliant. Loved the complexity of the story. In a way the character Cawl Remined me of the Doctor. I don't know if this is a spoiler or not, but was is the first rule when it comes to the Doctor? The Doctor lies.
5 reviews
October 11, 2019
The story jumped a bit, but the characters got depth and now Cawl is one of my favourite characters in the 40k lore. I never read alot about the Mechanicus, and Cawl may not be their best posterboy for the job, but hey, he has more style than any mech adept combined.

The book also gives us som insight in what has been going on the last 10 000 years and some of what the future brings in the dark world of 40K
134 reviews1 follower
April 12, 2020
Bit of a mess telling certain character view points due to temporal hijinks. And the big being of evil reveal did not mesh up to the names I recognized from previous lore. But Qvo and Felix and a few other space marines had some pretty interesting backgrounds that were given not nearly enough 'screen' time.
1,327 reviews19 followers
July 13, 2023
World of Sotha is utterly destroyed by Tyranid fleet. Newly assigned commander for the region, Decimus Felix, is tasked to oversee reassignment of Scythes of the Emperor chapter to this world. Scythes, led by their chapter-master Thracian, have arrived in system with a particular mission in mind and as a bonus (to Felix's delight) archmagos of the Imperium, Belisarius Cawl, also arrives in system to conduct his own investigation of ancient Pharos structure on Sotha (of Horus Heresy fame).

Three power players, Felix, Thracian and Belisarius will very soon open the multi-layered proverbial can of worms that just might be the high explosive bullet into the body of Imperium itself.

I wont go into much more details because it would be spoiler after spoiler.

What I can say is that author manages to wonderfully integrate three stories - one of control, one of uncontrolled seeking for knowledge (and decent amount of Indiana Jones' recklessness) and finally one of duty - and manages to add standard remote-abandoned-fort horror tropes with quite a few Indiana Jones/cyberpunk elements. Pharos, or better said the entire mountain it resides on, is also a character - background device triggering flashbacks in our heroes and producing quite a few golden nuggets of W40K lore. We are given some short views on beginnings of Astartes project in the Himalazian massif, end of Horus Heresy and power plays taking place in the background, return of Guilliman and introduction of Cawls role in Primaris genesis (Primus Alpha is excellent character) and also inner views of the artificial intelligences residing in mysterious Pharos mountain that was first visited by Emperor, then Guilliman and finally Mechanicum before Scythes of the Emperor established their fortress at the peak of the mountain.

Author manages to portray all protagonists (especially Space Marines) as a very likeable human characters, with fears (or whatever comes close to this for Space Marine) and doubts and sense of duty. Unlike usual heroes, like say from Aliens movies (because hey, you need to get close to slimy, alive matter no matter what - right?), here everyone is aware of the risks because they know what might come after them, so decision and actions are more impactful and with a goal to achieve. There is purpose behind everything, over or covert, latter developing over the course of the novel. Reader is left with tracking all of the story-lines and trying to piece things together as novel progresses.

Cawl, sort of a crazy genius "Dr Emmet" type is a backbone of the novel. Through flashbacks we are slowly fed reasons for this quest but he is constantly several steps ahead of both us and his entourage, always pushing the envelope in mission-impossible style. But even when doing all of what he is doing he is protective of his allies (although it definitely does not look like it to them personally). No wonder Guilliman is constantly upset with him.

Excellent adventure novel, written in a style that I definitely did not expect in W40K universe.

If you like stories of forbidden knowledge, mysterious planets and foes, and always those very much needed snapshots from the Terras past (with a juicy comment on Emperor himself) do yourself a favor and read this one.

Highly recommended to fans of W40K specifically and SF thriller/cyberpunk generally.
Displaying 1 - 30 of 162 reviews

Can't find what you're looking for?

Get help and learn more about the design.