The mystery of Edwin Drood is an unfinished novel by Charles Dickens. Authors have tried completing it with the few clues and facts in the book.

On August 18, 2010, Ben McDaniel disappeared after diving into a treacherous cave at Vortex Spring, Florida. He was never seen again.

In 1997, author Eugene Izzi was found dead hanging from a 14 story building in Chicago. Was it death, murder or suicide? The evidence is a mystery itself.

Rodney Alcala is a convicted rapist and serial killer sometimes called “The Dating Game Killer.” Alcala may have committed up to 130 murders.

Arguably the earliest instance of a plane whose pilot (and the plane itself) went missing is the 1910 disappearance of an aviator named Cecil Grace.

Grady Stiles Jr. led an interesting life and suffered a death that was just as intriguing. He was known as the Lobster Boy and had even committed murder.

On 10 April 1990, the crew took the Casie Nicole a fishing expedition. Five days later, only one man was found. The crew’s fate is a mystery.

Where is all the Fort Knox gold? Only a handful of people have been inside the vault, and there hasn’t been audit since the mid-1970s.