When books are first published there is a digital copy given to book reviewers so that they can give a review of the book. Apparently, someone had the digital copy of the second book and her fans were getting that copy for free. So, she changed the digital version so that it was not a complete book. Her fans were really upset and wanted to know where they could get the entire book.
The moral of the story: If you like someone's work, show your support and buy it. Do not cheat them. If you do, there may no longer be an option to enjoy the work of the author, music artist or movie company.