Just going to note that there seems to be an epic poem about the Heresy with plot relevance that shows up which is the extent of their knowledge, referred to as the Heretikhameron.
"Nine Sons who stood and Nine who turned. Nine for the Eight and Nine against the Eight. Eighteen all to make the Great Cosmos or bring it crashing down"- Pariah
Mine was a passage from The Heretikhameron, or 'Days of Heresy', a long verse poem written circa M32, which recounts the War of the Primarchs. I never read it all, and it was tortuously complex, but I remember the grand style of the opening book, with all its epic images and its declamatory tones, speaking of the 'Bright Emperor', and the Nine Sons Who Stood, and the Nine Who Turned. Sister Bismillah used to read it to me in the dormitory of the Scholam Orbus. I think the orphanage only had the first book in a little yellow volume. Anyway, my tempering litany is not just those words, it is Sister Bismillah's voice reciting them. She is, I suppose, the most maternal influence I have ever known in my life, so her soft voice was an important part of it.
So yeah, Bequin and Medea literally know what they do because they had a chance to read like Book 1 of the HH series in poem format.
That explains some “knowledge” but not all...
It’s arrived at long last! I was beginning to worry my order had been forgotten. I got the limited ed but the cover on the standard edition is beautiful compared to the limited edition. Wifey agrees. Unfortunately I know the main spoiler but can’t work it out. It’s also going to have to wait until after lambing to get read. I get the feeling it not one to be read on a coffee break at 2am.
A real shame you know the main spoiler! But you are right - this is NOT a dip in over coffee book. Enjoy!