discovers to her shame and horror, that her own father is in bed with Donna who is high on dope and has an affair with her step-father.

When Mom and Dad leave for a weekend in Las Vegas, Cindy goes to the beach with girl friend Karen (Cheryl Powell). Donna goes to Greg's pad where he talks her into "posing" for camera shots with two of his pals and ends up having affairs with both strangers. Obviously Greg is a no-good dope pusher using any girl he can. At the beach Karen has an affair with a pick-up on the beach but Cindy refuses her own pick-up date.

Back at Cindy's home, she and her girlfriend experiment with a joint of marijuana which Cindy has found in her sister's room. Both girls get high and Karen shows Cindy "how the boys do it - only better."

Next day Greg arrives to see Donna but she's uptight and won't see him. He makes a date with Cindy for next afternoon after school. She has decided to find out about sex from him. They are having an affair on the couch in the living room when Donna comes in and orders Greg to leave her young sister alone. He throws her out of the house bodily. Donna, in a daze, falls down in the street in front of the house and is hit by a car.

Horrified and now ashamed of what she's done, Cindy appears to have returned to her former innocence as she swings alone in a park.