The story begins with Kepler reading about a skillful magician named
Libussa. He falls asleep while reading about her. He recounts a strange dream he had from reading that book. The dream begins with Kepler reading a book about Duracotus, an Icelandic boy who is 14 years old. Duracotus's mother, Fiolxhilde, makes a living selling bags of herbs and cloth with strange markings on them. After he cuts into one of these bags and ruins her sale, Duracotus is sold by Fiolxhilde to a skipper. He travels with the skipper for a while until a letter is to be delivered to
Tycho Brahe on the island of
Hven. Since Duracotus is made seasick by the trip there, the skipper leaves Duracotus to deliver the letter and stay with Tycho. Tycho asks his students to teach Duracotus Danish so they can talk. Along with learning Danish, Duracotus learns of
astronomy from Tycho and his students. Duracotus is fascinated with astronomy and enjoys the time they spend looking at the night sky. Duracotus spends several years with Tycho before returning home to
Iceland. Upon his return to Iceland, Duracotus finds his mother still alive. She is overjoyed to learn that he is well-studied in astronomy as she too possesses knowledge of astronomy. One day, Fiolxhilde reveals to Duracotus how she learned of the heavens. She tells him about the
daemons she can summon. These daemons can move her anywhere on Earth in an instant. If the place is too far away for them to take her, they describe it in great detail. She then summons her favorite daemon to speak with them. The summoned daemon tells them, "Fifty thousand
miles up in the
Aether lies the island of Levania," which is Earth's Moon. According to the daemon, there is a pathway between the island of Levania and Earth. When the pathway is open, daemons can take humans to the island in four hours. The journey is a shock to humans, so they are sedated for the trip. Extreme cold is also a concern on the trip, but the daemons use their powers to ward it off. Another concern is the air, so humans have to have damp sponges placed in their nostrils in order to breathe. The trip is made with the daemons pushing the humans toward Levania with great force. At the
Lagrangian point between the Earth and the Moon, the daemons have to slow the humans down lest they hurtle with great force into the Moon. After describing the trip to Levania, the daemon notes that daemons are overpowered by the Sun. They dwell in the shadows of the Earth, called Volva by the inhabitants of Levania. The daemons can rush to Volva during a
solar eclipse, otherwise they remain hidden in shadows on Levania. After the daemon describes other daemons' behavior, she goes on to describe Levania. Levania is divided into two hemispheres called Privolva and Subvolva, corresponding to the far and near sides of the Moon. Privolva never sees Volva, while Subvolva sees Volva as their moon. Volva goes throughout the same phases as the actual Moon. The daemon continues the descriptions of Subvolva and Privolva. Some of these details are scientific in nature, including how eclipses would look from the Moon, the sizes of the planets varying due to the Moon's distance from the Earth, and an idea about the size of the Moon. Other details are fictional in nature, such as descriptions of the creatures that inhabit Subvolva and Privolva, plant growth on each side, and the life and death cycle of Levania. The dream is cut short in the middle of the description of the creatures of Privolva. Kepler wakes up from the dream because of a storm outside. He then realizes that his head is covered and he is wrapped in blankets just like the characters in his story. ==Publication history==