Joseph Donald Taylor turns 18 in southern Mississippi during the summer of 1955. He experiences a lot of changes and learns many lessons about life, love, and sex. The Summer of '55 is going to be the hottest summer of his life.
The dark stone changes those that possess it. Just after his eighteenth birthday, Sam finds a strange rock half-buried near some old abandoned train tracks. They were a normal suburban family. When Sam brings the stone home with him, things slowly unravel. His mother finds herself in situations she never imagined. His sister tries to resist her new impulses. Even Sam's married neighbor falls under the stone's spell.
Molly attends the wedding of her sister, but her husband can't come with, so she brings her son Tim. Tim's wife can't come either because she has to work. A twist of fate puts them in the same room at their hotel and an embarrassing tendency of Tim's makes for unexpected relations between mother and son.
Mary is about to embark on a month long vacation with her son Brad and daughter Carol. Complications arise when Carol invites her boyfriend along at the last minute. Carol's affinity for sex causes the family to adopt some unorthodox sleeping arrangement to accommodate Carol's libido. Mary's journey into the world of love and lust begins.
Sherry got very turned on by a website featuring people getting themselves off. When she slipped her hand into her pants to join in, she had no idea her son and his friend would be coming home from school soon. Sherry didn't know she had been caught until her son's friend's mother told her she had overheard the boys talking about it. Sherry had never felt so embarrassed in her life. She promised the friend's mom she would be much more careful in the future.