Rise of Endymion masterfully weaves together all the events from the earlier Hyperion sequence and Endymion. It plunges us deep into a strikingly different galactic milieu. Here, a revitalized Catholic Church holds sway, engaged in an epic struggle for supremacy. Pitted against it are the genetically modified Ousters, super-powerful AIs with enigmatic agendas, and a young girl named Aenea, who might just be the Messiah of a new era, along with her companion Raul Endymion.
Aenea is the offspring of the human woman Brawne Lamia and a cybrid named John Keats. She preaches a new religion that enables people to connect to the Void that Binds, which was severed from humanity at the end of Hyperion. This directly opposes the Catholic Church's Pax galactic empire, which is centered around the cruciform, granting unlimited resurrections to all church members who embrace it.
The story is vast and intricate, essentially the second half of the narrative begun in Endymion. It presents a fully-developed plot that meticulously extrapolates the consequences of the previous books and continues the underlying struggle and mystery involving the Core, AIs, humans, and Ousters. While I found it rather sluggish in many parts, especially when it became mired in various religious discussions, and there were far too many long-winded explanations by characters to clarify the story events, which would have been better integrated into the narrative itself. Nevertheless, one will undoubtedly gain a deeper understanding of the extensive machinations of the various players in this epic conflict, and most questions will be answered. There is, of course, an abundance of action and elaborate set-pieces. However, in my opinion, the book could have benefited from more rigorous editing and still would have been an impressive conclusion to one of the most ambitious SF epics of the past few decades.