[Excerpt: Flight of the Eisenstein] Battle-Captain Nathaniel Garro of the Death Guard brings word of Horus' betrayal to Rogal Dorn. Dorn is not happy with what he hears.

‘This is what you come to me with?’ The primarch’s slow anger filled the room like smoke, heavy and dark. ‘A convoluted story of treachery and conspiracy among the Emperor’s sons, a collection of ill-informed opinions and rash actions made with base emotion and not cold clarity?’ He advanced slowly on Garro, and it took all of Nathaniel’s courage not to back away. ‘If I were to have my brothers in this room right now, Mortarion, Fulgrim, Angron, Horus… what would they say of your tale? Do you think that you would even be able to draw a breath before you were struck down for such an outright fiction?’

‘I know it is difficult to accept—’

‘Difficult?’ Dorn raised his voice for the first time and the room shook with it. ‘Difficult is a winding labyrinth, or a complex skein of navigational formulae! This is against our very creed and character as the Emperor’s chosen warriors!’ He glared at Garro, eyes aflame. ‘I do not know what to make of you, Garro! You carry yourself like an honest man, but if you are not a traitor and a deceiver then you can only be possessed by insanity!’ He stabbed a finger at Qruze. ‘Should I make a concession for some contagious senility perhaps? Did the warp addle your minds and create this hallucination between you?’ Garro heard the sound of his blood rushing in his ears. Everything was going wrong, falling apart around him. In his rush to find a rescuer for the Eisenstein and a way to get the message out, it had never occurred to him that he would not be believed. He looked away.

‘Look at me when I speak to you, Death Guard!’ snapped the primarch. ‘These lies you bring into my personal chambers, they sicken and disgust me. That you would dare to say such things about a hero of such matchless character as my brother, Horus, it vexes me beyond my capacity for description!’ He placed a massive finger on the sternum of Garro’s armour. ‘How cheap you must hold your integrity to give it up so easily! I weep for Mortarion if a man of such low honour as you could rise to command a company of the XIV Legion.’ Dorn’s hand closed into a massive brass fist. ‘Know this – the only reason I do not tear you limb from limb for your defamation is that I know my brothers will reserve that pleasure for themselves!’

Garro felt the decking turn to mud beneath his boots and his chest caught in an invisible vice, returning to him the same sickening sensations that he had felt in the corridor outside the navis sanctorum and in the grip of the xenos war beast. As he had there, he reached for and found the strength of will that had carried him this far.

My faith.

‘Are you blind?’ he whispered.

Dorn was thunder incarnate. ‘What did you say to me?’

‘I asked if you were blind, lord, because I fear you must be.’ The words came from nowhere, even as some part of Garro marvelled at the mad daring of what he was saying. ‘Only one struck by such a terrible ailment could be as you are. Yours is the blindness that only a brother might have: that of a keen judgement clouded by admiration and respect, clouded by your love for your kinsman, the Warmaster.’

It was not often that Rogal Dorn’s stern mask cracked, but it did so now. The fury of a god made flesh erupted upon his aspect and the primarch drew his powerful chainsword in a flashing golden arc of roaring death. ‘I rescind my former statement,’ he bellowed, ‘get to your knees and accept your death, while you still have the chance to die like an Astartes!’

I'm reading through the Horus Heresy books for the first time and this scene really left me in awe at the sheer size of Nathaniel Garro's balls. Insulting the Primarch of the Imperial Fists on his own ship in front of his men? And the best/worst part is that he's right. Dorn is being blind to Horus' betrayal because he cannot believe that his brother is capable of throwing away everything they've fought for during the Great Crusade. I know a recurring theme of the heresy is the Astartes not even believing it possible for one of their own to turn against the Emperor, but this is the first time they show a Primarch's reaction to Horus turning traitor and I thought it was incredibly well done.