Revenge is frightening, but when you don't know who wants it, it's terrifying. A methodical killer has come to Brookfield. A retired law enforcement officer is dead. There's somewhere near Perla Lake who is patiently carrying out a plan of revenge-and Mac MacKenna doesn't yet know he's connected. Then his sister, Maggie, disappears without a trace. Suddenly, this isn't simply a murder in his small-town, it's personal. Mac spent his adult life being the person others could depend on when everything went wrong. Twenty years in the U.S. Air Force special operations taught him to run toward danger, find the person who needed him, and bring them home. But what happens when the person who needs saving is your own sister? Unknown Revenge taps into a fear most of us have never experienced-the inability to protect someone we love. It's about family, loyalty, old grievances, and the frightening reach of a person willing to wait for the right moment to settle a score. For readers who like their mysteries personal, Unknown Revenge asks: How do you stop someone seeking revenge when you don't know what they believe you did?