Marilyn Mitchell, a pretty 18 year old, disappears from her exclusive New England College - apparently without trace. Her eminent architect father offers a big reward and the only response is an anonymous letter assuring him she's visiting friends and will be back in a few days. When she fails to appear, the police begin searching for her body. Chief of Police Frank Ford doesn't buy the family's assertion that Marilyn is a nice pure girl. He believes a boy is at the bottom of the disappearance. Marilyn left behind a diary that doesn't seem to give any clues - or does it?