Travel back to the psychedelic '60s with two films from director Roger Corman. Jack Nicholson wrote The Trip, which follows the bizarre hallucinations of a movie producer's (Peter Fonda) acid trip. Dennis Hopper, Bruce Dern and Susan Strasberg co-star. Then, the accidental release of an experimental gas leads to the death of everyone over 25, leaving the youth of the world to run the planet in Gas-s-s-s.