The book contains a series of short stories linked by recurring characters. While each story could stand on its own, read together they add up, tracing the lives of those characters over several decades: from teenagerhood to success, from success to failure, from failure to recovery, etc. At times it is hard to keep track of the ways in which the stories connect, but in the end it doesn't really matter: you can lose track and still enjoy the book (I did). If one was to look for an overarching theme, without a doubt it would be time passing, and the experience of realizing that time has passed. I weirdly enjoyed the last chapter, set in the future, and especially Egan's guesses about the evolution of language.