It's a lot of ground to cover, but I read it in just a few days. This book succeeds because it takes the Inklings' orientation toward story to heart. The narrative is told as stories that make a single story, at times even with suspense-building tactics on the part of the Zaleskis. I stayed up late reading it even though I knew the ending.
Much must be edited out, but what is kept in is what most Lewis and Tolkien fans want to know. What did Lewis and Tolkien really believe? How did they sharpen each other? This provides the deep connective tissue of the narrative.
Only real flaw I can put my finger on at present is that of proportion: there's too much bio that can be gleaned elsewhere, and too little of the interaction between the Inklings. So little is recorded about the actual meetings that this is completely understandable, but I focused on anything about who influenced whom and what came from where -- the chemistry.
I think that some factual detail could have been sacrificed for more conjecture about the connections between, for example, Middle Earth and Narnia, or Williams and That Hideous Strength.
For example, the Zaleskis mention tentatively that Tolkien may have been influenced by Barfield. and quote Vernon Flieger. In my mind this is such a proven, sensible, and foundational connection that it underlines the importance of Barfield to the group -- but here, it is mentioned as peripheral. I don't mind such speculation; it's what makes a book like this sing! This book is about
the connections, not the nodes, and a shifted focus more toward the connections would have allowed more integration of the minor Inklings as well. As it is, many works are mentioned with little speculation on possible cross-influences. However, I have already read several books on and by each of the authors here, so a more general approach may fit the audience this is really for.
On the whole, the juxtaposition of the authors allowed me to glean some of the connections that I crave, and to relate it to my own work and writing, so I must highly recommend this unique and highly readable book to anyone with any interest in how creativity works, or how faith works, or how Oxford worked in the mid-20th century.