Jane’s mother dies at birth, and her father, a wealthy English aristocrat, soon remarries a woman who already has a son, William. William resents his new father and brother. Jane and her father George grow up dreaming of building a flying machine. George believes that distant Asian sands conceal a mysterious cerulean sand capable of making machines soar. He sets out on an expedition to find it, but is later reported executed for treason. William also disappears. After Jane receives an unsigned letter containing a handful of pale‑blue sand that floats in the air, she becomes convinced that her brother is alive and departs eastward to locate him and clear his name. Along the way, she and her new companions confront many mysteries that await them.