Fool's Run — Patricia A. McKillip

Terra Viridian is a young woman who obeyed a vision, took a laser assault rifle, and turned fifteen hundred innocents into light. She was captured, convicted, and sentenced to the orbital prison called the Underworld. Forever.

Seven years later: a bar-band pianist named The Magician suddenly plays Bach, while a riot burns around him. The Queen of Hearts, a drifter who hides her life beneath a golden mask, steps enigmatically from the shadows. Underworld administrator Jase Klyos unexpectedly lets a concert bring sound to his silent, sterile hell. And behind her mad eyes, the vision of a psychotic killer... changes. The thing that Terra Viridian saw is coming. Growing. Watching.

And it must be set free.