In 1913, a self-taught clerk from Madras sent a letter to Cambridge mathematician G. H. Hardy—an act that would quietly alter the course of modern mathematics. Srinivasa Ramanujan had no degree, no formal training, and little more than a notebook of strange, beautiful formulas. Yet, what began as a letter became one of the most remarkable collaborations in mathematical history, a story of intuition meeting rigor, faith meeting logic, and brilliance burning bright against all odds.