I did learn new information from this book, especially about Lewis' use of connections to Arthurian legend and other myths, but I did not enjoy reading it as much as other books analyzing Lewis' writings. This is the first book analyzing the Space Trilogy I have read, so it might just be the nature of analysis of the Space Trilogy.
This is a good guide to C.S. Lewis' Space Trilogy. It connects common thematic threads between the three stories that may be missed in a casual reading, some obvious and some less so. I particularly appreciated the explanation of the important role medieval cosmology played in the construction of Lewis' mythology and the highlighting of the parallels between Arthurian legend and the characters/events in That Hideous Strength. This would also be a good book to read for a reader who likes the Space Trilogy but is unfamiliar with the same ideas that appear in Lewis' other writings.