WATCH ONLINE, MOBILE, FREEVIEW 63, SKY 164, FREESAT 162 AND VIRGIN 216
The Ancient Astronaut Cover-Up: Apollo 14 astronaut Edgar Mitchell is among the experts discussing the possibility that aliens have been visiting the Earth for centuries. (S2, ep 1)
The Ku Klux Klan: Former Ku Klux Klan leader Johnny Lee Clary shares the secrets of the Hooded Order, including the extent of its power and its secret greetings and goals. (S2, ep 2)
American Nazis: Past and current Nazi members offer an insight into the US's secret Nazi past and the covert meetings and manifesto of its present-day Neo Nazi groups. (S1, ep 3)
Serial Killers: Experts investigate the motives of notorious American murderers as they question how the US has produced a staggering 1,400 serial killers since the 1970s. (S2, ep 4)
The Mafia: According to the FBI, the American Mafia still has approximately 3,000 active members. Could the Mafia's influence extend beyond local police and politicians? (S2, ep 5)
Deadly Cults: A look at the strange allure of cults, their leaders and how they control their members. A Jonestown survivor remembers the last days of the Peoples Temple. (S2, ep 6)
Presidential Cover-Ups: Go behind the headlines and uncover the real stories behind the greatest White House scandals of recent times. (S2, ep 7)
The Drug Wars: Documentary uncovering the conspiracies behind America's 40-year drugs campaign. Could laundered drugs money be keeping the fragile global economy afloat? (S2, ep 8)
Presidential Assassins: Explore the conspiracy theories surrounding assassinations of American presidents. Has the world been told the truth about their deaths? (S2, ep 10)
Hell's Angels: Informants and former undercover members of Hell's Angels offer a rare look at the international criminal syndicate and secretive outlaw motorcycle gang. (S2, ep 12)
Scientology: Former scientologists reveal what drew them to the church and why they chose to leave. An eye-opening look into the mysteries and allure of Scientology. (S3, ep 1)
Big Brother: Uncover how the US government secretly monitors American citizens and how its partnerships with Facebook and Yahoo allow it to gather data about its people. (S3, ep 2)
American Terrorists: A look at the secret measures employed by US authorities to hold back the thousands of terrorists thought to be operating on American soil. (S3, ep 3)
The Gold Conspiracy: Experts investigate the secret methods used to control the value of gold and why the US government could be overstating how much of it the country owns. (S3, ep 4)
America's Secret Armies: A look inside the US's secret services. These forces operate in the shadows, but what do they do? And do they have the US's best interests at heart? (S3, ep 5)
...of Secrets. Secret Prisons: Documentary exploring the biggest scandals and conspiracies to rock the US prison system, including Pennsylvania's 2008 'kids for cash' scandal. (S3, ep 6)
Billionaire Agenda: Investigation into the growing power and wealth of the US's super rich, including how billionaires' 'dark money' is being used to influence politics. (S3, ep 7)
Secret Underground: Uncover the cities and government fortresses covertly constructed beneath American soil, including an advanced network of drug smuggling tunnels. (S3, ep 8)
The Secret Service: A look at the scandals that have rocked the secret service, its gruelling selection process and the people and secrets its highly-trained agents protect. (S3, ep 9)
America's Doomsday Plan: From atomic attacks to cyber warfare and deadly airborne viruses, discover what the US government is doing to protect its people from danger. (S3, ep 10)
...Secrets. Series exploring the secrets of some of the most mysterious buildings and organisations in America, beginning with The White House. (S1, ep 1)
Freemasons: Unlock the mystery surrounding the hugely secretive and powerful brotherhood and discover the truth about their vision, meetings, symbology and bizarre rituals. (2 of 10)
Fort Knox: Discover the secret contents, political controversy and cutting-edge security lurking behind the gates of the most famous vault in the world, Fort Knox. (S1, ep 3)
Area 51: Unlock the secrets of one of the most covert military bases on American soil. What actually goes on at Area 51? And what is its link to the Roswell event of 1947? (S1, ep 4)
The Playboy Mansion: Peek inside the Playboy Mansion and uncover the truth about its decadent parties. Who is its most notorious guest? And how hard is it to get an invite? (S1, ep 5)
Presidential Transports: A look behind the bulletproof glass and armoured plating of the president's fleet of vehicles, from Air Force One to the limo known as The Beast. (S1, ep 6)
The FBI: An inside look at America's most powerful police force. Formed of Special Agents, its mission is public knowledge but its tactics are top-secret. (S1, ep 7)
West Point: Head inside the academy at West Point and discover the mysteries and traditions surrounding the secretive New York launch pad for presidents and army elites. (S2, ep 8)
Black Ops: The truth behind America's most dangerous and clandestine operations. What makes a top-secret assignment a black op? And how do soldiers prepare for them? (S1, ep 9)
The Pentagon: Enter the epicentre of America's military operations and discover how the nation's people and secrets are kept safe. (S1, ep 10)