In 1985, Peggy Sue (Kathleen Turner) collapses at her 25th high school reunion and “wakes up” back in high school in 1960. Knowing now what she didn’t know back in school, Peggy tries to avoid the advances of her boyfriend Charlie (Nicholas Cage). She knows that shortly before high school graduation, she slept with Charlie, gets pregnant and has to get married. But in 1985 her marriage to Charlie has fallen apart from his infidelities and is headed for divorce. Peggy Sue does everything she can in 1960 to change the course of her future she sleeps with the school jock, helps the school nerd invent panty hose and tries to give the lyrics to a famous Beatles song to Charlie so he can record it first and become famous.
Eventually, Peggy Sue goes to spend time with her grandparents and she and her grandfather go to his gentlemen’s club meeting where they try to help her “transport” back into 1985. Charlie kidnaps Peggy Sue during the ceremony and confesses his love for her. Peggy Sue realizes she loves him too and they make love basically not changing her history at all.
The movie fades back to 1985, where Peggy Sue is in the hospital. She had a cardiac event during the reunion and dreamed everything about going back to 1960. Charlie is waiting in the hospital room when she wakes up, and the two reconcile.