Paul Massie stars as Dr. Jekyll who is experimenting with bringing out the evil in people in order to study it.
The problem is is that things get out of hand and the evil Hyde takes over. Christopher Lee is Paul Allen, a man who has high gambling debts and is also having an affair with Jekyll's wife.
This is, as you can tell, basically a remake of Dr. Jekyll and Mr. Hyde. I have read a lot of reviews that say this film is boring and a let down. Granted, it is NOT an action film, but it is a very well made, story driven movie with fine acting by all involved. Dawn Addams makes a very sexy Kitty Jekyll.
This has been released by Mill Creek on a set with four other Hammer films called "Hammer Films Collection". The print is as good as the one released by Sony a few years ago. I like this film, and I would recommend it.