Schild’s Ladder is another Greg Egan book that was just awesome. In the first couple of chapters a group of scientists (very small scientists so they don’t need a very large spacecraft) perform an experiment that ends up oh, well, destroying the fabric of the universe. This disaster spreads at 50% light speed across the galaxy, consuming everything in its path. Then we jump to different characters who’ve been living with this thing that’s happening for centuries. There are different factions trying to figure out how to stop the boundary from expanding and others who’re content to run at 95% light speed, and our protagonist who wonders what’s on the other side. So fucking good.
The titular ladder is a way of transporting a vector so it stays parallel. Wonkiness of geometry means that if you take a different path, even though it remains parallel, you won’t end up in the same space. It’s all about travel really, and staying the same no matter how much you change and how much anyone else does.