I felt this was a very well written book and was very enjoyable to read. Luceno does a great job of portraying the famous Darth Plagueis and the life of Darth Sidious. The book fills in the many gaps left open from the movie and other books. We get to see how much of the grand plan was actually put into action by Plagueis and that he lived much longer than I thought based on the movies.
Another aspect about this book that I really like is that it brings many of the Old Republic ideas and intertwines with the Rise of the Empire era. We get to learn more of the Bane lineage in some detail as well as some other ancient sith sorcery.
The book begins at 67 years BBY and it goes through the books "Cloak of Deception, which Luceno also wrote, and also mentions the events of "Darth Maul: Shadow Hunter" by Michael Reeves, and ends at the ending of The Phantom Menace. It gives more a behind the scenes look at episode one; stuff they don't mention in the movie, which makes it much more clear.
Overall it is a solid book with much detail. I would recommend it to anyone who enjoys Star Wars novel.