Reunion scene: In the classroom of the repeat class for the senior year of high school, Lu Xiao discovered that the school ID photo of transfer student Jiang Yubai overlapped with the vague figure of the boy in his memory. When Jiang Yubai solved problems, he habitually traced the piano key map with a pencil. This move reminded Lu Xiao of the "note code" they created together when they were young.
Conflict foreshadowing: Mr. Jiang Yubai stayed alone in an empty classroom on a rainy day to play a broken piano. The star necklace Lu Xiao gave him when he was a child was hidden in the middle of the piano score (actually a token of love that was torn up by Jiang's father when he was escaping from the fire). Lu Xiao discovered that there were burn scars on the cuffs of his school uniform, which matched the characteristics of "the son of a school worker who was injured while saving experimental equipment" in the fire news report three years ago.
Metaphorical details: Jiang Yubai deduced physical formulas into musical notation, used Fourier transform to analyze the fluctuations of the piano music hummed by Lu Xiao, and found that when he was nervous, his little finger would press the keys for 0.3 Seconds longer.
Fusion of classic elements:
Lu Xiao filled the edge of the piano score with a rough draft of calculus, but disguised the function image as a staff;
Jiang Yubai used a thermodynamic model to measure the wind direction on the rooftop and tried to restore the sound wave trajectory on the day of the fire.
Intention: I don't know