A couple (Ray Lovelock and Cristina Galbo) travelling along the English countryside stop to get directions from a pair of Ministry of Agriculture workers who are testing an experimental device designed to drive crop-damaging insects into killing each other. While they plan their next stop, a man who has been dead for several days attacks--to be followed shortly thereafter by a full-scale zombie invasion--which could very well be a result of the agriculturist's distribution of ultrasonic radiation. A macabre, atmospheric Spanish-Italian co-production featuring extremely convincing performances and a haunting score by Giuliano Sorgini. The second half of the film contains enough gut-munching gore scenes to satisfy most horror fans, leading to an unexpected and eerie finale.