I've had this book on my shelves literally since ~1978 when it was published in paperback. It followed me through high school, college, marriage, career, and finally on the skids towards retirement. I'm slowly working through all the Hugo and Nebular winners and needed a book. What the hell...I grabbed it off the shelf.It's a great tale of the intersection of technology, religion, and fictionalized history. I was a bit perplexed by the ending. Was it even needed? Did he need to touch on the Starholmer's visiting Earth in the far future? It hinted at a future that could lead to another very interesting book, but it looks like Clarke did not leverage that ending in to another tale.