I cannot, I don't think, relate in words how utterly, gut wrenchingly, nail scrapingly bad this book is. However, this is a review. And as such I am, as you've probably guessed, going to try.
The Cabal plays into stereotypes. It plays into cliches. It staggers along without plot, without character development, without any form of direction whatsoever. I found the character of Roatax particularly painful, being a sole female (aside from regular damsels in distress who, not matter their circumstances, want to have sex with their captors).
The ending is insult to injury. Backwards and lacking in any form of satisfaction. Don't bother.
I bought this for pennies on the dollar because the Corgi cover looked buck-wild and the premise on the back promised a corny rah-rah action-heist. The first chapter was kind of interesting, the remaining character intros were... something, and then the story actually starts and the wheels fall off. The landing gear's gone, and it didn't take flight. It's cumbersome, idiotic, devoid of character, overlong in spite of its brevity, and lacks anything in the way of significant statement, speculation, or stunts.
Might make an OK movie if edited into unrecognizability, otherwise OK toilet paper.