I think there's potential there, reminds me of Warhammer, and the battle against Chaos.
Some grammatical errors, missing commas or commas in the wrong place.
The problem I find with it is that it reads like a quick summary of a larger story. Or maybe a prologue, rather than chapters 1 2 3 etc.
This line for example:
The voices became clearer..."great will the masters reward be to you"...he crept further along the narrow corridor they continued to speak..."The hordes will soon ravage this land, and then the world will fall to us"...
"he crept further along the narrow corridor they continued to speak" should probably be "as he..." or "corridor as they"
There's no description of the voice...if a demon voice does it sound just like a mans? If not then would Dune not know the speech of demons, and also why kill the commander so suddenly, with rage and anger maybe a shout of why the betrayal. Also would it be the case that dune would know that the hordes of chaos could reach and corrupt anyone, therein lies the danger of chaos and why the order is so important, so why would dunes training not prepapre him for the worst.
Also the ease in which Carth would kill the woman from childhood because she didnt fight off all the thieves...I find the actions of the characters too extreme. With no explantion other than "You left me...and I trusted you" ....had she a choice? would he not have thought that 'I hope Nahili had got away' rather than the other complete extreme, and if he joined the theives now (as i think so from that scene) would he not just think that she could join too.
I know they're your characters to do with as you will, but there needs to be bounderies on any characters behaviour in any situation. An air of realism in their actions based on the brief background you have provided.
Its sounds dramatic to start a chapter with the Betrayal and have character a betray b, but not when done simply for the sake of being dramatic. Unless a proper build up of the background and events that the characters go through is explained, and fleshed out in such a way as to say to yourself ' I can understand why he wanted to kill her now ', it wont work. I think his reasons are too shallow to hold any merit.
Just some things that come to mind. Hope some of that is helpful. I dont have time for more indepth discussion right now. <img src="/ubbthreads/images/graemlins/wave.gif" alt="" />