Five lives, eight centuries, and one battered book. In 1453, as the Ottoman army closes on the walls of Constantinople, an orphaned girl named Anna teaches herself to read Greek; beyond those walls Omeir, a boy born with a cleft lip, is swept into the besieging army and will leave it a deserter. In present-day Lakeport, Idaho, an octogenarian named Zeno Ninis works with a group of schoolchildren on a text he has translated from a crumbling Greek codex — in the same small public library into which Seymour Stuhlman, a teenager radicalised by the destruction of the woods behind his house, has carried a bomb. And decades from now, aboard the interstellar ship Argos, a girl called Konstance meets that same story, watched over by the vessel's artificial intelligence, Sibyl.
Their common thread is Cloud Cuckoo Land itself: an invented ancient tale, attributed to the Greek writer Antonius Diogenes, in which Aethon longs to be turned into a bird and carried to a paradise city in the clouds. Dedicated to "the librarians then, now, and in the years to come", it is a novel about the fragile, stubborn business of getting a story from one century into the next — and about the people, usually unremarkable and usually unthanked, who do the carrying.