This is definitely one of the most engaging and thought-provoking books on horror films I've read. The original edition of this book, published in 1973, has built something of a reputation for being the first serious in-depth study of English horror films - it was reading about this book in Jonathan Rigby's excellent 'English Gothic' which encouraged me to buy this book. And am I glad I did!
First the bad news. It's been poorly proof-read - possibly because of late delivery of the typescript (which would explain a lot of the book's shortcomings): the occasional missing full stop and comma isn't so much a problem, but when you come across a statement like 'Dracula was an invented image of Christ' you have to do a double-take to realise that there must be a typo ('inverted' surely). The index is very far from comprehensive - frustrating when the text refers to 'Selwynism' and there's no entry in the index to help you discover what Pirie means; downright frustrating when there are dozens of films covered in the text which simply don't register in the index. Finally, Pirie is rather light on films pre-dating Hammer's - Jonathan Rigby's book is much more informative in that area.
The good news is the text itself is clearly written by an enthusiast who has thought deeply about both the films and their literary background (Pirie is especially good on comparing the Dracula films with Bram Stoker's original character). He has also had access to many files from Hammer (the studio which is - inevitably - the main focus of his book) which reveals much about why and how certain films were made (most intriguingly the still little-known Joseph Losey film 'The Damned' - a seriously flawed movie IMHO, but still v interesting - which appears to have been an attempt to cash in on the success of 'Village of the Damned'). Sometimes his enthusiasm for Hammer product makes Pirie a little strident - in his fulminations against the 'realist' tradition of British cinema, for instance; or intolerant of anything which doesn't fit his concept of British horror, witness his rather puritanical disdain for 'The Abominable Dr Phibes'.
The book has been extensively revised in this new edition, Pirie revising his opinion on certain films and acknowledging the sterling work done in recent publications (eg Wayne Kinsey's 'Hammer: the Bray Studio Years'). A final chapter, 'Towards a New Horror Mythology', usefully brings the book up to the films of 2007 (including such recent fine works as 'The Others' and 'The Descent'), though there are - perhaps inevitably - few profound insights, though plenty of sound judgements, and some sloppy writing (a sudden sprinkling of exclamation marks around pp197-98 again suggesting minimum proofing). Altogether, though, an excellent book which I urgently recommend to all fans of British horror films.