Some teenagers are driving again in a van. They run out of petrol, the usual thing. The group split up and half of them go off to look for petrol. And that's when it starts to get scary because you know when you get split up from somebody or you've arranged to meet someone and they don't turn up. It was another one of those kind of end of the 60s kind of movies, I think. A bit like Black Sabbath, that kind of evil vibe that came after the sort of idealism of the60s.