The archaeology professor Hopper is searching for a group of missing hippies, including his parents and sister, that disappeared in the 70's in a cave where there is a legend that has the Fountain of Youth. He finds a man that does not move inside a cave and returns home, where he releases his students Taylor and Jackie from the research saying that he will proceed the work alone. Hopper never returns and Taylor asks his girlfriend Cara to borrow her father's Jeep to look for Hopper. They go with Cara's sister, the teenager Veeves and her teenage friend Furby and find Hopper's car. They enter the cave and need to use ropes to abseil down to a lower floor. When they decide to climb to leave the level, the ropes frail and Taylor and Jackie hurt. Soon they find Furby dead with a broken neck and his video footage shows that many days have passed by outside the cave, but they have spent only one hour inside the cave. Taylor concludes that time moves slower inside the cave, and there are dangerous cavemen inside.