This is pure Hammer and, therefore, utterly lovable- if hardly worthy of admiration. It is an entertaining period horror which is taken very seriously by the actors and less so by the effects staff (see how they shrink back in fear as the magnified backscreen projection of a tarantula or a horse with cardboard wings stalks them!).
By modern standards it's about as scary as being attacked by a goldfish being neither psychologically disturbing or making you jump, but that isn't the point. It is entertainment- more thriller than horror. Christopher Lee is a deeply sinister hero, Charles Gray a compelling villain and the script races along with surprising depth and a refreshing lack of predictability.
If you can show me another film where Prime Minister Jim Hacker knocks out a bloke from Emmerdale Farm with one punch, I'll eat my hat. 6/10.
