Season 4

Ancient ruins fascinate us, and some archaeological finds are so baffling that they challenge everything we know about the past. Will we ever learn the truth about these mysterious ruins? Or will they continue to present more questions than answers?

Genius is widely considered to be the ability to change the world in an incredible way: inventing new technology, deciphering the mysteries of the universe, or creating transcendent art. But where does genius come from? What is the X-factor that makes someone a genius? Is it "good genes"? A proper education? Or do geniuses tap into something much more mysterious and extraordinary?

More than 80% of the Earth's oceans remain unexplored, and in many ways, the underwater world is the final frontier. As new technology allows us to explore oceans and deep lakes more than ever before, what will we find? Will we discover profound secrets about the oceans? Underwater ruins that were lost for thousands of years? Or perhaps something even more extraordinary?

From the ancient Babylonian's to modern day urban explorers, mankind has always been fascinated by abandoned places. What is the allure that draws us to these post-apocalyptic landscapes? Is it simply morbid curiosity? Or, something harder to define? Could abandoned places actually be places of 'magic'--as the ancients believed? Well, that is what we will try and find out.

There are some events that are so destructive, so astounding, or truly miraculous -- that for the faithful -- they must be directed by the hand of the Almighty. The Great Flood. The Plagues of Egypt. Sodom and Gomorrah. Moses Parting the Red Sea.

The animal kingdom is full of deadly predators, and some of them attack in extraordinary and inexplicable ways. Do some animals strike back at humans for reasons beyond normal defense and hunger? Can they have emotions like anger or a desire for revenge? Despite our technological advancement, do animals pose a greater threat to us than we realize for reasons that we cannot explain?

Throughout history, humans have buried their dead in caves or chambers, in pyramids or in some form of a tomb; ancient tombs were visual memorials for the dead; in China, a vast necropolis was constructed as a way to connect to the afterlife.

All over the world, there are places and objects that are thought to be cursed; many people avoid these locations and things, believing they will bring harm, while others think that curses are nothing more than superstition and folklore.

Whether surviving freezing temperatures, diving unfathomable depths in one breath, or lifting weighty objects, superhuman feats never cease to amaze; pulling them off could be a matter of training, willpower, genetics, or something more mysterious.

Today, human civilization spans the globe, and there are more than 7 billion people on Earth. But how did humanity evolve? Although many around the globe believe that the divine hand of God placed homo sapiens on Earth, were there other kinds of human-like creatures--cousins of man--that could have been just as intelligent as us? And if so, might these other species still exist today, perhaps in remote parts of the world?

Humans can survive catastrophic injuries and deadly scenarios that defy the odds in ways that are inexplicable; these survivals challenge the best attempts to explain how anyone could live through such circumstances.

King Arthur, England's first pop culture superhero; his exploits inspired blockbuster movies and television series like "Middle Earth", "Harry Potter", "Game of Thrones" and "Star Wars"; the significant impact of Arthurian legend on Western culture.

Remarkable feats of engineering from our ancient past span the globe. Some are amazing in size. Others in sophistication. Some are so strange they border on inexplicable. Did the ancients have advanced scientific knowledge that has been lost to time? How--and why--did they fashion these incredible wonders?

Who was Jack the Ripper? The question has baffled police investigators, historians, and armchair detectives for over a century. Countless books, movies, and television shows have been based on the Ripper's murderous exploits each with their own unique take on the killer's identity. Was he an accomplished surgeon? A member of the British royal family? Did he actually exist at all? Over 130 years later, are we any closer to the identity of one of history's most notorious serial murderers?

Space. The Final Frontier--and the ultimate mystery. Scientists are involved in a never-ending quest to understand the vast universe our planet inhabits. But it seems that for each answer science provides, even more questions arise. Our own solar system is populated by mysterious objects and phenomenon that seem to defy our attempts to understand them. And when we get deeper into space, the mysteries only deepen. What could lay beyond the confines of the Milky Way? Are there galaxies similar to our own? Could they be capable of sustaining intelligent life? And is that life trying to contact us?

For centuries, fantastic tales of terrifying monsters have fascinated mankind. Bizarre beasts of all shapes and sizes have been portrayed in some of history's most classic stories and folklore. But what if these creatures were more than just works of imagination and superstition? Could these stories of legendary creatures be inspired by actual events and where does the line between fact and fiction fall? Do these famous monsters still lurk in the dark corner of our globe today?

For hundreds of years there have been legends of vast treasures hidden throughout the United States. Stories of stolen gold, piracy, murderous revenge, but are these legends of lost treasures tall tales? Or is it possible that these valuables are out there, waiting to be discovered?

All over the world are forbidden 'triangles'--mysterious regions where ships, planes, and people enter and then just disappear. They are found in Bermuda, Alaska, Japan and elsewhere. But why? Do these locations defy the laws of physics? Or is it possible that there are some places on Earth that we are simply not meant to go?

The Founding Fathers established the pillars of freedom and democracy in the United States; more than two centuries after their bold vision came to life, new information has emerged about the agendas and secrets of these important historical figures.

The American frontier is full of legends of cowboys, Native Americans, and outlaws. But there are also many eerie stories of cursed mountains, monsters and even UFOs. Could these tales be true? Is the Wild West much stranger than commonly though?

In our modern world, we tend to think that technology and scientific knowledge can help protect us from almost anything, including natural disasters. But is that really true? Or are we just as vulnerable today in the face of raging fires, violent earthquakes, and destructive hurricanes as our ancestors were in the past?

All over the world, there are giant monoliths that our ancient ancestors carved out of solid rock. But what was the purpose of these huge stone monuments? Did they serve some kind of ritual function? Were they intended to honor the gods? Or is it possible that, as some believe, certain monoliths were actually designed to conduct energy?