Peggy Davis Johnson went out for drinks in Murphysboro on a summer night in 1995 and was never seen again.
Her sister says Peggy liked to party, but did a night on the town lead to her death?
The last person to see her told police he dropped her off with a friend, but police and Peggy's family don't believe that.
On Monday night, we'll take you back to that night and show you the reasons why police believe something very bad happened to Peggy that night.
Maybe you saw something that night. Maybe you've heard something about Peggy's story that could help solve this 21 year old cold case.