They thought they had all the power—until she took it from them. Now a Scottish police detective must find a vigilante in the midst of a media storm...

A killer hunts abusive spouses, blogging about their sins post-kill. Soon the bloodshed—and the brazen posts—draw the attention of Police Scotland's CID.

This murderer works with surgical preparation, precision, and skill, using a unique weapon of her own and never leaving a trace of evidence behind. Edinburgh's DI Kathy McGuire, nearing the end of her career, begins the hunt as a media frenzy erupts. But McGuire might have met her match in a woman who is either driven by desperation to take the law into her own hands—or simply an ice-cold killer.