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Three children's stories — about a princess, a soap-bubble umbrella, and a hungry king — composed by Yun Tianming under Sophon's surveillance and transmitted home, each one secretly encoding a piece of the only physics that could save humanity.
The fairy tales are Yun Tianming's farewell letter to the species, written in the only code Sophon would not censor. The first story encodes the existence and engineering principles of the curvature drive (the soap-paper boat). The second describes the black-domain refuge as a kingdom inside a fog. The third hints at the dual-vector foil. The IDC's decryption committee took years to read them; AA spotted the curvature drive within an hour, in a fountain, with a fingertip.
Plain text, transcribed in their delivered form into hundreds of languages. Each story is short — a few thousand words — and apparently a children's tale in the tradition of Chinese, European, and indigenous folklore. Illustrated editions appeared within months. Most copies sold to children.