The investigative series hosted by Robert Stack returns with segments on Elvis Presley's alleged suicide; and claims by Michael Landon's stepdaughter that the late actor has contacted her from beyond; murder of two young prostitutes; anonymous tip leads to buried bones.

Unexplained Death: Monika Rizzo Unexplained Death: Gloria Ross & Candy Belt

Probing the mysteries of the ancient Nanteos Cup, believed by some to be the Holy Grail. The vessel s reputed to hold the power to heal those who drink from it.

A grainy gas-station video may hold the key to finding an Illinois girl missing since she set off on a joyride to Florida with her boyfriend, who was later found murdered. Other segments include a Vancouver, Wash., family who claims to share their home with spirits.

Townspeople of a British village offer a theory that a 300-year-old chair in a local pub can cause the deaths of those who sit in it. Also: an e-mail message taunts the police with grisly images of law officers; authorities seek clues to the death of a 6-year-old Texas girl.

Phoenix residents claim they saw odd, V-shaped lights in the skies when the Hale-Bopp Comet passed over the southwestern U.S. in 1997; a California woman discovers that she has three brothers and possibly three additional siblings.

Repeat of November 11, 1997 episode

Unexplained Death: Monika Rizzo

Repeat of April 3, 1998 episode

Wanted: Luie Quezada Wanted: Michele Lee Abraham Missing: Mary Agnes Gross Unexplained Death: Kathy Page

Repeat of April 10, 1998 episode

Wanted: Michael Wayne Brown Wanted: Ngoc Van Tran Missing: Shannon VerHage Missing: ""Pat"" (Amnesia Victim)

A grainy gas-station video may hold the key to finding an Illinois girl missing since she set off on a joyride to Florida with her boyfriend, who was later found murdered. Other segments include a Vancouver, Wash., family who claims to share their home with spirits, which may be tied to an 1800s murder. (Repeat)

Wanted: Marshall Lee Brown Wanted: Jose Francisco Blandon Missing: Wendy Von Hubben

Townspeople of a British village offer a theory that a 300-year-old chair in a local pub can cause the deaths of those who sit in it. Also: an e-mail message taunts the police with grisly images of law officers; authorities seek clues to the death of a 6-year-old. (Repeat)

Wanted: Francis Buhay Update: Wanted - Trent Stephen Fouts Unexplained Death: Katherine Korzilius Wanted: Paul Ragusa