At Madrid’s Teatro Real, the hall fell silent when Plácido Domingo stopped mid-performance, his eyes caught by a handwritten sign: “I got into Stanford. You said we’d sing.” The sign belonged to Emily Carter, once a foster child who had met Domingo backstage at just nine years old. That night, he promised her: “When you get into college, if I’m still singing, we’ll sing together.” Years later, the promise came true. Domingo brought her on stage, and together they sang — trembling at first, then soaring — a moment of destiny fulfilled.