Hammerhead (Peter Vaughan) is a dangerous international criminal suspected by British Intelligence of trying to steal NATO defense secrets. In desperation, a young, charming soldier of fortune is called in to match wits and guts in man-to-man combat with Hammerhead. His name is Charles Hood (Vince Edwards) and he operates in London (the wilder parts) and moves on to the Portuguese coast in pursuit of Hammerhead and pursued by pert, kooky London model Sue Trenton (Judy Geeson). Written by filmfactsman

When the vehicle of a group of road-tripping beauties is sabotaged, the girls find themselves lost in the woods of Wing Brook, Kentucky. They soon discover they are not alone. Stalking the woods is Hammerhead, a ruthless human hunter who hibernates with the 17 year cycle of the local cicada bugs. The girls only hope for survival rests in the revenging hands of Killian, hellbent on finding the predator that took his sister's life. Three stranded Vacationers, an avenging brother out to settle the score at any cost, and Hammerhead - will the nightmare end - or merely hibernate for another 17 years. Written by ITN