‘I suppose I do not need to ask,’ said Guilliman, reaching for a slender, leather-bound volume. ‘But if I do, then in time you will see me for what I am, and not what you believe me to be. A god has no need for manners. There are other factors.’

Guilliman held out the book.

‘Let us leave your certification for now, if you wish, but take these notes of mine. These are the topics I would like the blessing to cover. You claim to represent the Emperor’s word. You are better placed to speak His will and obey my orders, and resolve neatly any contradictions there might be between the twain. A delicate time lies ahead. I cannot rule by diktat alone. Every institution does as I ask, for I am the Imperial Regent. I am the Emperor’s living agent. But I am no tyrant, and I will not become one. I will have all the Imperium at my back willingly, or we will fail. I cannot become my brother Horus.’

‘Nobody said you were a usurper, my lord,’ said the priest, and took the slim book from the primarch’s hands. His fingers shook. In terms of paper and leather, it weighed hardly anything, but there was responsibility there enough to crush a horde of saints.

‘The most dangerous thoughts go unsaid,’ said Guilliman. ‘Many think it.’

He turned back to his datasplays and hololiths,. The conversation was over, but the priest remained. A moment later, Guilliman looked over his shoulder.

‘Still here, priest?’

‘I have one more question, if you might indulge me,’ said Mathieu.

Guilliman picked up a stylus and began marking a data-slate, where a list of new finds for his library glowed greenly. He began ticking off the books he desired to see soonest. ‘You want to know why I chose you. Why not a cardinal, or the Ecclesiarch himself? It is only natural.’

The priest nodded. ‘I am the lowliest sort of priest, my lord,’ Mathieu said. ‘Even in the Missionara Galactica, I am beneath notice. My ministry is with the poor, and the sick. It carries no prestige and not a little disdain. I have never craved power or influence. I simply desire to do your father’s work. That is reward enough for me.’

‘Well said. That is exactly why I have chosen you, and not some princely demi-pope. You care. You fight alongside my armies, and you care for the meanest serf.’ Guilliman’s noble face became more solemn. ‘And I have heard your sermons.’

‘You have?’ said Mathieu. He was surprised and honoured, but still he did not fall to his knees and start wailing. Guilliman was satisfied he had chosen well.