While there isn't a literal fictional "story" about this specific PDF, the journey of M.C. Chaki's Textbook of Tensor Calculus
Practical Use: Beyond academia, these tensor principles are now the backbone of modern Machine Learning, used to decompose complex data into actionable insights. Textbook of Tensor Calculus - M. C. Chaki | PDF - Scribd
Key Topics: It covers the transformation of coordinates, summation conventions, covariant and contravariant vectors, invariants, and Riemannian geometry.
Professor M.C. Chaki, a prominent figure from the Calcutta Mathematical Society, wrote the Textbook of Tensor Calculus