I have this book and its not in the same league as Norris- Newman's . The Forbes book is 54 pages , my copy is a paperback.
From what I remember the story is being told by Capt . N.A. Walford R.Art. going back to Forbe's thoughts and then issuing an
answer from Chelmsford's point of view ! . A little confusing but worth reading if you can get a reasonably priced copy .
I will attempt to find a link , I know its on ebay but not sure of the price .