This book was shocking to me, although my husband loved it.  I thought that the author choose two characters who were as diametrically different as two members of the same species can be.  The reader knows that Alex Cross is complex.  He would have to be to become a forensic psychologist in the first place; and  work for the F.B. I.; have a wife who was murdered by a psycho,  have all of the outrageous experiences he has had, have the guilt of what happened to his wife, and now he gets the chance to capture the murderer.  The other guy, who crawled out from under a rock to do some more sick stuff.  I never read a book in which the character, Michael Sullivan, is more twisted, maniacal, and so thoroughly enjoys the horrible and ruthless  things he does.  Once you begin to read this book, you’re hooked and you have to finish it; but I won’t be looking for the sequel.