What would you do if your loved one vanished? Would you know where to look? Investigators believe it's the last hours before their disappearance that are the most critical to finding them alive. Often people who vanish have secrets. But how do you uncover them? In this compelling investigative series, we explore some of the most baffling disappearances from across the country. Each 30-minute episode chronicles a race against the clock, as investigators gather the facts and piece together the clues that ultimately might save them.