I've been watching the Hammer and Bolter animated series on Warhammer+, and I'm reviewing each episode as I watch it. There may be very minor spoilers, but ideally no more than you'd get from the episode description.
One of the things I like about Warhammer stories is that they aren't about a great rebellion. Don't get me wrong. Somebody needs to topple the Imperium in the Warhammer universe, and somebody needs to mend that pesky Eye of Terror to stop Chaos from leaking out into the galaxy. But then what would happen? Most modern sci fi assumes that the only "correct" story arc is that a band of plucky heroes blows up a space base and brings down an entire empire, replacing tyranny with...um, Freedom and Democracy and stuff. There's a vague sense of USA-style "righteousness" to the solution, and while it can be cathartic, it also often feels insincere and more than a little naïve.
Warhammer stories don't have to tackle this problem. The setting exists primarily for a wargame, and if a wargame needs anything, it's war. It benefits almost every aspect of the Warhammer universe for there to be ceaseless conflict. And while it's profoundly sad to say so, it's also realistic. The real world struggles, historically and currently, with the push and pull of theocracy, greed, destruction, and fanaticism. There's no all-powerful central "off" switch for a band of plucky heroes to target, and even if there were, the heroes would be too busy working three concurrent part-time jobs to go on the adventure. The stories in Warhammer 40,000 are sci fi but they ring true in the sense that they're stories about people going about their daily lives, with no regard to their maligned aspirations, depraved morals, horrendous surroundings, or hopeless future.
That's kind of what Bound for Greatness is about.
The entire story is set in a great library, where monks are told by their superiours that "knowledge corrupts" and "do not read". Seems like an odd message for attendants of a palace of books, but those are the rules. Every day, the attendants count books on the shelf to ensure, I guess, that none are missing.
Pretty early into the story, though, one of the monks notices that one of the books is missing.
I have to admit that, like Death's Hand, I'm not entirely sure I understand the end of this episode. Unlike that one, though, I'm not sure you're supposed to exactly understand this one. I get the idea, anyway, and it's dismal no matter how you look at it.
If you're not clear on why Warhammer's universe is considered grimdark, this a good episode to remind you. In a way, I guess it's one of the most pro-rebellion stories I've seen within Warhammer so far. But if it is, it also ends exactly the way you'd expect a rebellious storyline to end in Warhammer: In the heavenly glow of the Emperor's terrifying and oppressive "glory".
EDIT: I've watched the Deep Strike analysis of this episode, and apparently it's a Tzeentch cult corrupting the librarian monks. I don't know how you're meant to know this, aside from the concept of corruption. There's also a very quick cut of some book text changing from "Emperor of Man" to "Changer of Ways", and that cut did register with me when I first watched it, but I missed it and didn't backtrack to figure it out.
This episode is OK sci fi. It hooks into the existing worldbuilding of 40K and tells a simple story. There aren't many sci fi elements, though. It's speculative fiction, more than sci fi, and that's fine.
This episode is great Warhammer 40,000. I don't think this story would have the same impact if it were told in any other setting. Prior knowledge of the Emperor of Man, the Imperium, and maybe the Warp and Chaos (maybe? I don't really understand the ending, so it's hard to say what forces did what) are required for this story to work. This episode fulfills the promise of grimdark.
Ideally, anyone watching this story is reminded how the Imperium isn't the Good Guy. You don't get to escape the Imperium by rebelling against it, and worse yet you don't get to escape the Imperium by accepting it.
All images in this post copyright Games Workshop.