Comfortable New York suburbanites Arthur and Gerrie Mason discover one night that their seemingly perfect 16-year-old daughter Maxie has been using LSD. Arthur immediately suspects his 17-year-old son Artie of supplying the drug to his sister, and kicks him out. Whereupon a confused Gerrie seeks advice from high school principal David Hoffman, whose family has their own problems. Very sensibly, he advises love and understanding on part of the parents, which all but goes out the window when Maxie confesses that not only has she been tripping for some time now, but is also sexually active and on the pill.