Each year, hundreds of thousands of people are reported missing in the United States alone.
Why did a Swedish teenager on an Australian adventure mail a cryptic letter to his family in Stockholm before disappearing forever? What became of a young woman whose car was found crashed and abandoned off a cliffside in Whatcom County, Washington? How can an individual vanish without a trace in.
The majority of those who disappear turn up within a week, but a small percentage are never heard from again.
Each year, hundreds of thousands of people are reported missing in the United States alone