Cross Your Heart III — James M. Matheson

Fiona Donovan has had a rough life. Her sister, murdered. Arrested, persecuted, nearly killed. There is a deadly side to her city that she never knew existed, and without meaning to Fiona has waded deep into a world of crime, sin, and death. It's a lot for a girl just looking for justice. When things look darkest, there's usually a silver lining to find. Not for Fiona. Her world is about to explode. Literally.