I read this book years ago. It was about Neanderthal man never dying out and living in our society. They were stronger than us and had secret societies within the U.S.. They would use us to keep their secret. The story was about a cop who married a woman who was a neanderthal and the things he did that revealed her secret to him. I know it's a shot in the dark but if anyone has read a book like this let me know. I'd like to check it out again.