2. Civil War

From a secret society that gathers in the dead of night and plots the assassination of Abraham Lincoln to U.S. spymaster Alan Pinkerton who stops Confederate agents, the outcome of the Civil War is often decided by spies.

3. The Vatican

The Vatican is a secretive, watchful institution that protects its reputation and the members of its ranks with fierce, often reckless abandon. But the secrets and scandals throughout its history are some of the darkest in all of history.

4. Gold

Gold ...one the most rare treasures on Earth. Since ancient times, man has gone to extreme and often deadly lengths to get it. But where is most of the gold today, and who owns it?

5. Secret Prisons

Lost to the hands of time... or intentionally covered up, the dark history of America's Secret Prisons will be revealed.

6. Code Wars

American code breakers have given the United States an edge in every conflict in American history. But with uncrackable encryption available for your cell phone and computer, have U.S. code warriors finally met their match with enemies who have perfected.