The book

Yes, sometime shortly after it was published. And as good as the movie is, the book is even better, as it has many different stories interwoven together that the movie had to eliminate or at best refer to with a few seconds of footage (Houdini, etc.). Not that I fault the movie for that in the least, as they took the primary story & followed it beautifully through to the end. The transition from page to screen almost always requires some changes, after all. I was not disappointed by those changes in the least.