>>> what in fact happened to sarah stern? >> sarah's car was found early on a saturday morning. >> she just disappeared. >> just vanished. >> what do you guys have this thing listed as? a missing person? >> hello. police department. >> there's nobody in the house. >> had she been different than normal litly? and for how long? >> in the past she has had a tendency to have self-destructive, suicidal behavior. >> how could this girl just commit suicide? >> if she did jump off the bridge, what are the odds that she's not out in the ocean? >> something is not right here. maybe this wasn't a suicide. maybe she was murdered. >> this is the last time we see her face. >> still can't find sarah. wondering where sarah is. >> they were sarah's friends. they had been making this dark, bone-chilling plan. >> you are the only person on this planet that knows. >> when you saw the video, what was your reaction? >> i need a minute. ♪ >> tell us about neptune city, new jersey. >> neptune city is this small little sleepy, tight-knit community rig