A good script from Hammer stalwart Jimmy Sangster who also wrote the excellent Paranoiac, and matched by sharp direction and photography. A shame, then, that the cast are such a let-down. The well-known ham Donald Houston lives down to his reputation - his voice was dubbed, a pity that his performance couldn't be erased. The French actress Lillian Brousse is excellent as the innocent daughter, but the American Kerwin Matthews makes for a very anodyne lead. The rest of the cast are British, utilizing French accents straight out of 'Allo 'Allo. Hammer have made some excellent non-horror movies such as Taste of Fear, and but for the dreadful acting this could have been one of them.