Cloud Cuckoo Land by Anthony Doerr is a historical science fiction novel published in 2021. Doerr is an American author, winner of the Pulitzer Prize for his novel All the Light We Cannot See, and recipient of numerous other literary awards. Cloud Cuckoo Land blends elements of fantasy and science fiction with unconventional organization to create a complex world of plots relating across generations. The title of the work humorously refers to a phrase used in literature and philosophy that critiques utopias and those who believe in them. This guide uses the original Scribner publication of the book by Simon and Schuster.

Plot Summary

The plot follows five main characters through three timelines. The characters are: Anna and Omeir in and around 15th-century Constantinople; Zeno and Seymour whose plots converge in 2020; and Konstance, who lives in the future. All the plots are connected through the Cloud Cuckoo Land folios, a fictitious Ancient Greek story that follows Aethon as he endeavors to find a utopia known as Cloud Cuckoo Land. The 24 folios of Aethon’s story introduce each chapter. These chapters jump from character to character, switching perspectives throughout.

The book begins by introducing the five main characters and Aethon’s story, as fictitiously discovered by the real-life Greek philosopher Diogenes. Anna is a young orphan living in Constantinople before the Ottoman siege; Omeir is a Bulgarian boy born with a cleft lip who is enlisted into the Ottoman troops. Zeno is a shy child, orphaned after his father is killed in World War II, who goes on to serve in the Korean War. Seymour is a neurodivergent child who befriends a great grey owl he names Trustyfriend. Zeno and Seymour meet in 2020 when an attempted act of environmental terrorism by Seymour goes awry. Konstance is a child living on the Argos, an intergenerational spaceship that has allegedly left Earth after the planet is destroyed by climate change. The characters all face internal and external conflict when they learn that the world is more complex than they thought in a coming-of-age plot.

Anna struggles with being more curious and courageous than most other girls during her time in history. She sneakily learns to read and later risks her life to steal books from an abandoned priory. When selling these books to mysterious Italian buyers, she learns the value of preserving old stories and the risk of allowing a select few to exclusively possess books. During the siege of Constantinople in 1453, she must accept that her city is not infallible. She flees as the city falls, taking her precious copy of the Cloud Cuckoo Land folios, and meets Omeir. Ridiculed his entire life for his physical deformity, Omeir finds friends in animals instead. Enlisted into the Ottoman troops against his will, Omeir learns that the world is full of destruction and cruelty. He rejects this side of human nature and flees the war, running into Anna on her journey away from Constantinople. They end up living a happy life together, both enjoying Anna’s copy of Aethon’s story. After Anna’s death, Omeir takes her book to ensure its survival.

Zeno is an anxious child who struggles with his father’s death. During Zeno’s service in the Korean War, he is taken prisoner by Chinese soldiers. His time in the prisoner-of-war camp is defined by his crush on his fellow prisoner, Rex Browning. Rex introduces Zeno to Greek translation before he escapes, leaving Zeno to be liberated by American troops. Zeno longs to be with Rex after the war, but when they meet in 1971, Zeno is too scared to confess his feelings. In retirement, Zeno feels his life is unfulfilling until he meets five children at the Lakeport Public Library who change his life. The children learn about his translations and work with Zeno to produce a play of Cloud Cuckoo Land.

Seymour lives with his single mother who struggles to provide for him. As a neurodivergent child, Seymour does not fit in. He finds comfort in the forest outside their home, especially with his beloved Trustyfriend. When the forest is demolished by housing developers, Seymour becomes obsessed with climate change. He is slowly radicalized by Bishop, an internet persona who advocates for extreme retributive actions against climate destruction. Seymour attempts a bombing at the Lakeport Public Library—the building that neighbors the housing developers responsible for the forest’s destruction—on the same night that Zeno and the children are doing their dress rehearsal. The bombing does not go as planned, and Zeno confronts Seymour. When the bombs are remotely detonated, Zeno carries them outside to save everyone, dying in the process. Seymour is sent to prison, where he works to compile Zeno’s translations of Cloud Cuckoo Land as penance for his actions.

Konstance’s life aboard the Argos is fraught with existential dread when she learns that she will never live long enough to reach the spaceship’s destination. She spends her time wandering through a simulation of Earth, known as the Atlas, in the ship’s virtual library. When a disease breaks out and sends the crew into panic, Konstance’s father saves her by locking her in Vault One, the ship’s intelligence center that operates independently. Inside the vault, Konstance discovers what happened at the Lakeport Library in 2020. She also finds Zeno’s translation of the folios. Through these discoveries, she finds “triggers” in the Atlas revealing that Ilium—the company that makes the Atlas and Argos—has been censoring their images of Earth. Back in the 21st century, Seymour places these triggers in the Atlas while working for Ilium after he becomes suspicious of the company’s motivations for censoring images in the Atlas. Konstance learns that the Argos’s mission is also a lie and the ship is still on Earth. She escapes the ship and creates a life for herself on Earth, and with her she takes her homemade copy of Zeno’s translation of the Cloud Cuckoo Land folios.

Aethon’s story begins when he drunkenly sees the play The Birds and thinks it is a depiction of a real utopia, Cloud Cuckoo Land. Despite everyone’s warnings, Aethon embarks on a journey to find the utopia. He mistakenly transforms first into a donkey then into a fish, as he travels the world inconvenienced at every turn. When he finally becomes a bird, he flies high into the cosmos and discovers Cloud Cuckoo Land. He becomes bored in the utopia because life there is perfect. Faced with the choice between staying forever in Cloud Cuckoo Land and returning home, Aethon realizes that his life needs balance to be fulfilling—something he cannot achieve in the utopia.