On an unseasonably warm winter evening in Pennsylvania, 15-year-old Patty Desmond sneaked out through the basement of her house. She had a history of running away, and that, combined with an argument with her mother, gave police reason to suspect she'd come home in a week or two.

The year was 1965. That night was the last time her family ever saw her.

Conrad Eugene Miller was well-known to local law enforcement. An older married man with a child, Miller's association with Patty was questionable at best. Yet he was the last person known to have seen her alive-and the suspect police continued to circle back toward.

After nothing but false sightings and rumors, the case was moved to the backburner-where it stayed. As decades crept by, reality sunk in: Patty Desmond was never coming back. Then, a tiny crack unleashed a flood of information, and a mystery that had never quite been forgotten was solved.