Was a monstrous killer brought to justice or an innocent mother condemned? On an April night in 1989, Jo Ann Parks survived a house fire that claimed the lives of her three small children. Though the fire at first seemed a tragic accident, investigators soon reported finding evidence proving that Parks had sabotaged wiring, set several fires herself, and even barricade her four-year-old son inside a closet to prevent his escape. Though she insisted she did nothing wrong, Jo Ann Parks received a life sentence without parole based on the power of forensic fire science that convincingly proved her guilt. But more than a quarter century later, a revolution in the science of fire has exposed many of the incontrovertible truths of 1989 as guesswork in disguise. The California Innocence Project is challenging Parks's conviction and the so-called science behind it, claiming that false assumptions and outright bias convicted an innocent mother of a crime that never actually happened. If Parks is exonerated, she could well be the "Patient Zero" in an epidemic of overturned guilty verdicts--but only if she wins. Can prosecutors dredge up enough evidence and roadblocks to make sure Jo Ann Parks dies in prison? No matter how her last-ditch effort for freedom turns out, the scenes of betrayal, ruin, and hope will leave readers longing for justice we can trust.