It’s only a couple of thousand words long, and still online, so follow the link and read it!
The title relate to the names of four very special weapons created centuries ago by Arighan. Shiron owns/is owned by one of these weapons, and the clever conceit of a story that reflect on effects of actions have echoes into the past, rather than into the future, is that having used the weapons before understanding what it can do, Shiron has found out to her cost, and those of her ancestors, and humanity as a whole, exactly how powerful the guns are.
It’s a short story, an appetiser that leaves you wanting more. In Alastair Reynolds’ hands it would be the opening chapter of a 1,000 page novel.