Matter is one of Iain M. Banks’ Culture novels. So it’s a far-future adventure full of interesting post-humanity and alien ways of living. There’s a group of people living in a gunpowder/artillery tech society on the 8th level of a Shellworld, and they’re at war with the similar folk on the 9th level. Now this Shellworld is maintained by aliens as habitats for these cultures. The aliens aren’t supposed to interfere technologically or what have you. Basically because it wouldn’t be very polite. But our viewpoint characters are three siblings from this primitive culture and their king/father has been assassinated to dastardly ends. One of these characters left long ago and is now a posthuman member of the Culture. One sibling is trying to get a hold of her to get her help, while the last is the prince-regent who’s oblivious to the fact that his regent is the guy who killed his king.
It’s a good adventure tale (and the ending is satisfyingly abrupt for someone like me who gets a little bored of action sequences in books) but the theme of the different layers of significance is what makes it compelling for me. Everything is insignificant at some level, but that doesn’t mean you don’t do anything. It seems like an important thing to remember sometimes.