In the besieged city of Constantinople in 1453, in a public library in Lakeport, Idaho, today, and on a spaceship bound for a distant exoplanet decades from now, an ancient text provides solace and the most profound human connection to characters in peril. They all learn the story of Aethon, who longs to be turned into a bird so that he can fly to the paradise of Cloud Cuckoo Land, a better world. Twelve-year-old Anna lives in a convent where women toil all day embroidering the robes of priests. She learns to read from an old Greek tutor she encounters on her errands in the city. In an abandoned priory, she finds a stash of old books. One is Aethon’s story, which she reads to her sister as the walls of Constantinople are bombarded by armies of Saracens. Anna escapes, carrying only a small sack with bread, salt fish—and the book. Outside the city walls, Anna meets Omeir, a village boy who was conscripted, along with his beloved pair of oxen, to fight in the Sultan's conquest. His oxen have died; he has deserted. In Lakeport, Idaho, in 2020, Seymour, a young activist bent on saving the earth, sits in the public library with two homemade bombs in pressure cookers—another siege. Upstairs, eighty-five-year-old Zeno, a former prisoner-of-war, and an amateur translator, rehearses five children in a play adaptation of Aethon’s adventures. Konstance, encased on a spaceship decades from now, has never lived on our beloved Earth. Alone in a vault with sacks of Nourish powder and access to “all the information in the world,” she knows Aethon’s storythrough her father. Konstance, Anna, Omeir, Seymour, the young Zeno, the children in the library are dreamers and misfits on the cusp of adulthood in a world the grown-ups have broken.