Pamela Franklin never really got the credit she deserved as an actress: she was so convincing in everything I saw her in. Here she is believable as a young nurse caught in a terrifying trap in an unfamiliar country. Dressed simply but nicely throughout, she has a doe-like quality here which makes her seem all the more vulnerable. Michele Dotrice is lovely as well (wish she could have been seen more in films). The late Sandor Eles was unknown to me at the time, but quite good. While not overly menacing or devastatingly handsome, he did possess an interesting charisma. All of the actors cast helped add to the aura of atmospheric suspense.
The DVD: The film's theatrical trailer, radio spots and talent bios are included, as well as commentary by director Fuest, screenwriter Brian Clemens and Christopher Lee biographer Jonathan Sothcott. I rate the commentary as okay but I don't know why they bemoan the fact that they did not cast a different actor to play Paul. Did they have someone else in mind? I would like to have heard more about Pamela Franklin as well. Some commentaries I like to listen to more than once; this isn't one of them. It could have been better, but it's not the worst commentary I've ever heard.
In conclusion, this is one suspense film you can watch during the day and still get a good scare. Recommended.