
The story revolves around fifteen-year-old pilot Claus Valca and navigator Lavie Head, who fly their vanship as sky couriers in the nation of Anatoray. Although they usually take up missions of relatively low difficulty, they are one day asked to complete the mission of a dying courier. The mission, rated seven stars out of ten, is to deliver a young girl named Alvis Hamilton to the mysterious battleship Silvana.[11] Despite their fears, Claus and Lavie deliver Alvis to the battleship but decide to remain aboard to keep her safe.[12]
Claus and Lavie are initially treated as intruders but eventually befriend the crew of the Silvana. They learn that the Guild intends to capture Alvis for reasons unknown to them. In the first battle between the Silvana and Guild forces, Guild member Dio Eraclea takes an interest in Claus’s flying skills and his signature move, the Immelmann turn.[13] Wanting to learn more about Claus, Dio willingly allows himself to be captured by the Silvana. He reveals to Alex Row, the battleship’s captain, the existence of one of four Mysteria which act as a key to something known as Exile.

