A secret society gathers in the dead of night and plots the assassination of President Abraham Lincoln; U.S. spymaster Allan Pinkerton stops Confederate agents before they can topple the Union.
The secrets and scandals surrounding the Vatican are some of the darkest in all of history.
Since ancient times, man has gone to extreme and often deadly lengths to get gold, one of the rarest treasures on Earth; looking at where the gold is today and who owns it.
A secret part of history has remained hidden, locked away for centuries in the hulls of ships in New York and in the depths of an abandoned copper mine.
American code breakers have given the United States an edge in every conflict in American history.
American Nazis hold rallies at New York's Madison Square Garden in the 1930s and plot to steal the nation's weapons secrets.
Investigating the possibility that alien beings helped construct pyramids and other earthly monuments; Swiss author Erich von Däniken's works challenge religion and science.
Secrets of gambling mecca Las Vegas include the city's connection to organized crime, crafty tricks used by casinos and why the Nazis considered it a target for sabotage.
Investigating the United States' most infamous cults, from fire-and-brimstone organizations to those worshipping visitors from space.
The U.S. government attempts to create telepathic supersoldiers in the days of the Cold War; criminal Whitey Bulger volunteers to take part in a top-secret CIA mind-control program.
Secrets involving the federal penitentiary on Alcatraz Island, including the escape of three prisoners and the remnants of a strange military outpost with ties to President Abraham Lincoln.
Investigating UFOs and the strange stories surrounding them, including the existence of a "shadow government" and the rumor of a Nazi flying saucer that crashed in New Mexico.
An examination of underground bunkers, from their use in ancient wartime planning to the hidden survival complexes found beneath modern American cities.
Bordellos, which have endured for thousands of years, hold secrets involving famous patrons, governments and religion.
Many of the Founding Fathers and 14 U.S. presidents were members of the secret society known as the Freemasons.