In the mid-1980s, the Therac-25 was hailed as the future of cancer treatment. A computer-controlled radiation therapy machine, it replaced physical safety interlocks with software logic. But a microscopic "race condition" in the code-a millisecond timing error-caused the machine to deliver massive, lethal overdoses of radiation to unsuspecting patients. This book provides a haunting forensic analysis of the software engineering culture that allowed these errors to persist. It exposes how a single programmer's overconfidence and the lack of independent testing transformed a life-saving device into a silent executioner. The investigation traces the harrowing experiences of the victims and the slow realization of the manufacturers. Learn the technical mechanics of the bug that changed the field of software safety forever. It is an essential reference for understanding the ethical burden of automation and the catastrophic consequences of ignoring the "human-in-the-loop" principle. A devastating study of what happens when we trust the logic of a machine more than the warnings of the people who operate it.