CNN's Brooke Baldwin reports on a mystery that began in small towns across the Midwest. Several young girls went missing. Some were found murdered. Others were never found at all. And all of these cases went unsolved. Investigators believed only one man knew what happened. To get answers, it would take a risky, unusual plan: send a convicted drug dealer undercover into a dangerous prison to befriend an alleged serial killer. At stake: answers, peace for grieving families, and one man's freedom.

Film Duration: 41 min