folk investigate a strange series of murder on a tiny island be be attack and kill by an unseen presence . this moody british horror film be make several year before the stalk n slash genre kick off and yet this atmospheric chiller possess a number of element that would later become popular in the modern horror genre . at the same time it have the sense of an old gothic horror film a well and with it gloomy atmosphere and dark setting . the story may be simple but it combine enough scene of shock violence and creep suspense and and steamy sex to keep one engage throughout . a little campy and yes and but it only add more to the fun of this guilty pleasure . the cast be adequate and highlight by such veteran actor a bryant haliday and jill haworth and and mark edward . in addition the gore effect be also well do and provide for some effectively chilling scene . for fan of the slasher genre or 70 horror in general and tower of evil be an enjoyably eerie trip . out of .