Paul Groves (Peter Fonda), a television commercial director, is in the midst of a personality crisis. His wife Sally (Susan Strasberg) has left him and he seeks the help of his friend John (Bruce Dern), a self-styled guru who's an advocate of LSD. Paul asks John to be the guide on his first 'trip'. John takes Paul to a 'freak-out' at his friend Max's (Dennis Hopper) pad. Splitting the scene, they score some acid from Max and return to John's split-level pad with an indoor pool. Paul experiences visions of sex, death, strobe lights, flowers, dancing girls, witches, hooded riders, a torture chamber, and a dwarf. He panics but John tells him to 'go with it, man.' Would you trust John?