After rushing from his home, Rey Rivera disappears. Days later, his car is found — and a strange sight at a historic hotel triggers a baffling mystery.

Patrice Endres abruptly vanishes from the salon she owned within a 13-minute window of time. Exactly 600 days later, her case takes a shocking turn.

When an aristocrat and his entire family disappear, the authorities unearth something horrifying.

Alonzo Brooks vanishes after a party. His body is found a month later. Many believe that his unsolved death is a hate crime.

Residents of Berkshire County, Massachusetts, recall their baffling, terrifying experiences with a UFO on the night of September 1, 1969.

Lena Chapin claims on tape that her mother killed her stepfather. Several years later, she's issued a subpoena to testify in court — then disappears.