Book of Souls by Glenn Cooper is the second in the series featuring Will Piper. I highly recommend reading the first in the series, Library of the Dead, otherwise I don't think you will understand the story. I did read Library of the Dead and was glad to connect the dots.
In the Book of Souls, Will get caught up in finding a missing book, that was one of the ones written in Library of the Dead. He was trying to help a couple of FBI colleagues. They were retired, as he was. But one of them, made a deal with Will that involved too much money--a deal he couldn't refuse.
In getting the book back and solving the mystery the book led Will to, he encounters medieval letters from Shakespeare, John Calvin, and Nostradamus. Of course, this is all a violation of the agreement Will made with the government. Will almost gets killed. But his wife, Nancy, saves him.
Good, because there's a sequel. Stay tuned.
