Wow. Just wow. The novel begins in 2019 at the Arecibo Observatory when the program there picks up a transmittal of music from Alpha Centaury. The Jesuits are the ones that sponsor a mission to the system and send a team to the planet, Rakhat, to explore. It is clear from the beginning that only one of the team - a priest by the name of Emilio Sandoz - survives the mission and the story is therefore told in flashback, alternating between what happened on the mission and his relating the story in the contemporary time. Sandoz has returned to great controversy because the Jesuits sent the mission without UN oversight and because it ended terribly. Sandoz returns as a shell of the man that he was and we are left to sort out why.
This book was simply amazing. Doria deals with many heavy subjects in such a terrific way: the benefits and risks in absolute faith in a benevolent God, the role of God in the lives of people who believe and people who don't, and how that would effect interactions with aliens or other sentient human beings. Science fiction is simply the vehicle through which she elected to explore these themes. Very little is spent on how they figure out how to travel through time and space. The struggles of the characters aren't necessarily with the technology but with their own thoughts, beliefs, misconceptions, actions, follies and relationships. I loved that this was an exploration of what happens when a person tries to do things for the right reasons and yet, things go wrong. GO BUY IT NOW!!!