Books on Sapphire & Steel are very few and far between, in fact this is the first ever guide book to the series to be published. It's a fairly slim volume, but then there were only ever 6 televised stories and virtually no merchandise, so the amount you can write about the series is inevitably going to be limited. In here you get a brief background to the creation of the programme, little biographies on the main actors and behind the scenes personnel, synopses of each story complete with cast lists, transmission dates etc, trivia, ongoing developments in the series mythology, goofs and an indepth analysis of each story. This latter feature is easily the best thing about the book, each story getting several pages of critique. Some interesting points are made, and while I didn't always agree with the author's opinion of the merits of each story, he covers every point of each story in a good amount of detail and the reviews made me appreciate certain aspects of the stories I hadn't noticed before. There is also a look at the range of audio stories which also get shorter reviews but were again interesting critiques.
Overall, for anyone interested in Sapphire & Steel this book is a must buy. It will tell you just about everything you could want to know about the series, although as even it's creator PJ Hammond admits he never really knew who Sapphire & Steel were and what was really going on, prefering to leave an aura of mystery to the programme, so it's the sort of show you can't really analyse that deeply. This book is probably as in depth as you're going to get.