She was noticed. She was warned about. She was never stopped.

On a winter night in January 2006, a former postal worker entered a mail-processing facility in Goleta, California, and turned a system of order into a site of terror. By the end of the night, six people were dead. So was the woman who killed them.

This book is not a procedural reconstruction of violence, nor a search for easy explanations. This is a meticulously reported, novelistic examination of how catastrophe is assembled quietly-over years, across institutions, through missed warnings and bureaucratic blind spots.

From a withdrawn childhood in Brooklyn to a restless search for belonging in California's civil-service systems, from untreated mental illness in rural New Mexico to the moment grievance becomes action, the life of Jennifer San Marco is traced with restraint and precision. Her notebooks, her encounters with police and clinicians, her legal purchase of a firearm-each fragment reveals a system that saw danger without acting decisively.

The victims are remembered not as numbers, but as people: parents, coworkers, ordinary lives interrupted.

Unflinching and humane, this is a study of institutional failure, moral complexity, and the unsettling truth that tragedy is rarely sudden. It is cumulative.