Hi, I was wondering if anyone could help me discover the title of a book I owned some years ago. It was about a cop/federal agent who discovers dark magic run amok on Earth while investigating the suicide/murder of one of his college professors. It involved ley lines, giant tuning forks and ultimately he and his comrades end up at Stonehenge and confront a great evil. The cover of the paperback was all black except for an outlined drawing of a tree that had a pentagram carved into it. The drawing itself was red. For some reason I thought the title might be "The Other" or "The Others" but I have tried Googling it with no success. Sorry for the lack of detail.