One winter, a message startled Kayla awake at three in the morning. The subject line: “Does anyone know how to find a lost voice?” She opened it to read a woman’s plea: her father, once a radio host, had lost the confidence to speak after an accident. He could whisper now, but his laugh had gone. The thread filled with suggestions—speech therapists, gentle improv exercises, reading aloud in the car—but the turning point came from somewhere Kayla hadn’t expected: Anil, the retired signalman, who wrote that he used to hum to the trains when he was lonely, and that humming had returned when the platform light shifted green. “Tell him,” he wrote simply, “to find the light that changes.” The phrase read like a riddle.