Fancy a bit of daemon-hunting in the 40k universe? Within these walls is a short story by C.Z. Dunn is a 1930s-style haunted Egypt story, except Egypt is the agriworld of Niebuhr and 1930s is 40,000s. It's a good story, featuring Sister Agentha of the Orders Dialogus of Adepta Sororitas as its main protagonist. This is my review of the story, with spoilers (although to be fair, it's about a daemon in 40k, so how meaningful are spoilers?)
The Orders Diagogus is a non-militant division of Adepta Sororitas, so they don't often feature in stories set in the universe of a popular tabletop wargame. Maybe it's a case of knowing your audience, but this book puts a lone linguist, who sits around translating ancient texts all day, as the hero of the story. I don't recall her firing a gun during the course of the story, and she's constantly pushing her glasses back up onto her face as they slip down her nose. As far as relatable heroes in Warhammer 40,000, Sister Agentha ranks high.
The description of the short story from the old Black Library site, and graciously preserved on [Lexicanum.com](https://wh40k.lexicanum.com/wiki/Within_TheseWalls(Short_Story):
When the tomb of a daemon is discovered on the agriworld of Niebuhr, Sister Agentha of the Orders Dialogus is sent to decipher the markings on the structure. Guarding her are Space Marines of the Exorcists Chapter, whose affinity for all things daemonic is well known... and feared. But as Agentha translates the ancient script, she realises a terrible truth: The daemon is gone. Where is it? And will any of them survive its wrath?
A team of Imperial surveyors uncover a tomb on Niebuhr. When they approach the door, strange runes appear on it. They summon the neighbourhood (or Niebuhr-hood?) Adepta Sororitas order, which is the Orders Dialogus. Sister Agentha, having been stranded on Niebuhr through a series of circumstances that happened in stories I haven't read yet, is deployed to the tomb to help. When she arrives, she is able to translate an inscription, and it warns of a daemon.
Well, once someone utters the word "daemon" in 40k, you can expect either the Inquisition or space marines. In this case, the space marines are faster to arrive I guess, because a mysterious squad shows up and promptly assumes control of the site. I don't recall them ever actually identifying themselves (Agentha asks outright, and they decline to respond) but the story's cover art explicitly features the chapter marking of the Exorcists. They're a no-nonsense squad who are on high alert and ready to bomb Niebuhr out of existence to stop a daemon, the trouble is that when they arrive they find no sign of a daemonic presence. Sister Agentha insists that her translation is correct, so they decide further investigation is warranted.
When they enter the tomb, they find inscriptions on every wall, from floor to ceiling. Strangely, the writings are in dozens of different languages. Some are so ancient that Sister Agentha doesn't even know them. The space marines decide that a transcription of the writing would be useful, because maybe the inscriptions reveal how to find a daemon, which obviously they would love to know so that they can kill it. The space marines tell Sister Agentha that they'll remain on Niebuhr for as long as she needs to make a transcription for them, so she gets to work.
Every day, a space marine accompanies Sister Agentha into the tomb, and holds a bolter aimed at her head as she works. Better safe than sorry, after all. It's a little unnerving, but Sister Agentha is as curious as they are to unravel the mystery of the missing daemon.
The mystery, of course, is unraveled by the end of the story and, as you might have suspected, the daemon was there all along! There's a big epic battle between the space marines and the daemon, lives are lost, heroes are made, and our lone linguist shouts some arcane syllables into the chaos. I won't spoil the details, or who makes it out alive.
Within these walls isn't horror, but it's also not your typical Warhammer 40,000 story. Its main character is a scholar, but as with stories that feature tech-priests you don't actually get to see Sister Agentha translate stuff. You don't get insight into the great puzzle that she must solve. The story happens around the knowledge that Agentha is hard at work, doing scholar stuff, but the actual narrative we read is mostly about Agentha's relationship to the space marines, and her efforts to get herself off Niebuhr and back to her Order. As readers, we just accept that a bunch of scholarly work is being done, but I think that an actual linguist would probably be disappointed to find very little procedural detail, just as I'm always a little disappointed not to hear the specifics about how a tech-priest overrides a broken connection or works around a malfunctioning system. It's understandable, and the author does a really good job of making us believe that Agentha is a real nerd doing real language-nerd stuff.
The story's good, and it successfully presents Sister Agentha as a likable character, and then puts her life in danger so you spend most of the book hoping she manages to escape her obvious fate. It's a Warhammer 40,000 story, so you know things can't go very well for her, but there's still the question of how good or how bad things get. Read the story to find out!