Every evening, Mira sat on the underpass steps and played the same eleven notes. She never named the tune. It just showed up in her fingers one cold winter and stayed. Coins dropped into her open case while she played. But tonight a padded envelope was already waiting on the step. The address was written in her own slanted handwriting, even though she had never mailed a thing in her life.

Mira didn't open it. She shoved the envelope in her coat and watched the crowd. Someone had to be playing a trick on her. Then she spotted a woman across the underpass, standing very still, staring right at her. The woman lifted one hand in a small wave.

Mira crossed the underpass toward the waving woman. Up close, the woman's face stopped her cold. It was her own face, older, with gray streaking her hair. 'I don't have long,' the older Mira said. 'I came back to warn you. Don't open the envelope tonight.'

Mira promised not to open it. But after the older woman vanished, the envelope felt warm in her pocket, almost begging. She held out for an hour, then gave in and tore it open on the walk home. Inside was a single word in her own hand: 'Run.' Behind her, footsteps started to follow.

Mira ran, clutching her instrument. The footsteps stayed right behind her, matching her pace exactly. She spun around to face whoever it was and found no one there at all, only the echo of her own boots on the concrete. The chase had been herself the whole time. Shaking, she finally let the song go.