When Beth leaves for summer camp, the diarist returns to her hometown to stay with her grandparents.
She meets an old school acquaintance, who invites her to a party.
One night Sheila and her new boyfriend introduce the girls to heroin and brutally rape them while they are under the influence of the drug.
Traumatized, the diarist and Chris move to Berkeley where they open a jewelry shop.
Over the following days the diarist socializes with the other teens from the party, willingly uses more drugs, and loses her virginity while on LSD.
She worries that she may be pregnant, and her grandfather has a minor heart attack.
The diarist befriends a hip girl, Chris, with whom she continues to use drugs.
Her friendship with Beth ends, as both girls have moved in new directions.
They eventually drug her against her will; she has a bad trip resulting in physical and mental damage, and is sent to a psychiatric hospital.
There she bonds with a younger girl named Babbie, who has also been a drug addict and child prostitute.
Questions about the book's authenticity and true authorship began to arise in the late 1970s, and it is now generally viewed as a work of fiction written by Beatrice Sparks, a therapist and author who went on to write numerous other books purporting to be real diaries of troubled teenagers.
Nevertheless, its popularity has endured, and as of 2014 it had remained continuously in print since its publication over four decades earlier.
The diarist's father, a college professor, accepts a dean position at a new college, causing the family to relocate.