The name is FOOLS DIE. It was Puzo's follow up to the Godfather, so it was eagerly anticipated and started off selling well. But, if I recall correctly, sales started to drop off immediately after people started reading it and talking about it. It's the story of a rich old casino owner, and his number one guy. There's a plot, of course, which I don't really remember too well, but I do remember that it's filled with a ton of symbolism and allegory, and was a tough read. The writing style is far from the simplistic one used in GODFATHER.