I'm never quite sure about Catherine Coulter. I have at one point or another read all her books, starting way back when she just wrote historical romance. I enjoy her plots - I'm a person who loves series because I like to get to know characters, and she writes that part very well. I just can't ever get over how oddly her characters talk. It just always jars me to hear her characters' conversations where there aren't any contractions or the language seems so formal and stilted.
That aside - and if you read her, I bet you know what I mean - this was a good installment. Without giving spoilers, a question gets answered from the last story. The ongoing characters are well developed and grow some, as people do.
The plot is, well, over the top. I am both a mystery and a romance reader. I do NOT pick up the likes of Catherine Coulter, Linda Howard, Julie Garwood and their ilk for the realism of their police procedures. I go to Kathy Reichs, Linda Fairstein, Deborah Crombie and so on for that. This one, in particular, seems to throw all investigative technique out the window and relies nearly solely on the FBI folks' intuition and the ubiquitous Max. There is also (no surprise, I hope, since the book's about a psychic's widow) a strong supernatural element to this book, which may turn off readers like my grandmother, who loves authors like Coulter or Nora Roberts, but won't read any of their books that feature ghosts or witches or the like.
Again, this is a series book. Most of us dedicated series readers will buy or read series books until the author makes some huge character mistake or the writing just goes completely into the toilet. So, if you read the FBI series, you'll probably want to read this, no matter what I say. And, what I have to say about this book is not at all bad - I felt that it was a good installment for this particular series. And, if you've not read any of this series before, this is not the place to start. You'll be confused, you won't have the emotional attachment to the characters, and you might not be as willing to forgive some of the oddities of the writing.