In the 1980s, a suspected serial killer preyed on women in small towns located on the banks of the Mississippi River until the murders abruptly ceased and went unsolved. In 2006, 26 years later, a cold case detective and producer on the set of "Cold Case Files" unknowingly began to connect the dots that would crack the case while discussing the murder of Deborah Sheppard, a Southern Illinois University student whose death had remained a mystery since 1982.