Children of God (Ballantine Reader's Circle) by Mary Doria Russell
The Sparrow introduced us to a rich cast of characters who shared a journey that might seem unlikely, but at the hands of this writer became completely plausible. This book takes us into the year following that story, and updates us on the lives of those we came to love in the first novel. While her storytelling is equally as rich in both books, the events of the first book preclude some of the emotional attachments we formed there. A must read for anyone who read The Sparrow, but I am not sure that it can stand alone.