Patricia Cross and her boyfriend Larry Osborne , two students in a San Francisco school , become expelled for the publication of an off-campus underground paper .  As a result , a philosophy professor , Dr. Jonathon Barnett , resigns his teaching position and decides to become an advocate for the counterculture youth movement and , specifically , the use of LSD .  The hippies of the Haight-Ashbury district first see him as a hero and then as something even more .  Dr. Barnett even makes an appearance on the Joe Pyne TV show to voice his support of the hippie community and the use of LSD .  One scheming young man sees the opportunity to build Dr. Barnett as the head of a cult centered around the use of LSD .  He hopes to earn profit from the users , Dr. Barnett's speeches known as `` happenings , '' and their lifestyles .  At a massive LSD-fueled dance , Patricia begins to have a bad trip Which leads to an argument between her and Pat , ultimately splitting the couple up .  After Patricia realizes that she's pregnant , Dr. Barnett advises her to have an abortion , ultimately leading to Patricia attempting suicide .  However , Larry saves her and makes the destruction of Dr. Barnett's cult his primary objective .  Larry shoots Dr. Barnett from the crowd at one of his massive speeches .  As another hippie in attendance calms the audience and Elliot sees his new leader for their cult-like organization , Larry realizes that his assassination of Dr. Barnett simply made him a martyr for the hippie movement . 
Larry shoot's Barnett after vowing what?
To make destroying the cult his primary objective