For decades, the debate has raged as to what exactly Unidentified Flying Objects--or "UFOs"--really are. Theories have been put forth that attribute them to everything from secret military aircraft to weather phenomena and more. But by far, the most controversial theory is that these objects are, in fact, spacecraft that have been piloted to Earth by extraterrestrial beings. It's a seemingly outlandish notion, but could it be true? And if so, how much does the government know about these spacecraft--and the aliens who are visiting our planet?

For centuries, humanity has looked up at the Moon with a sense of wonder. But is the Moon just a rock floating in space? Or could it hold profound secrets—and perhaps even possess incredible powers? That is what we will try and find out.

Our five senses--sight, smell, hearing, taste, and touch--construct the reality of the world around us, like a blank canvas continuously painted and repainted over every day. For each person, this portrait of reality is slightly different, but we more or less agree that the sky is blue, lemons are sour, and horns are loud. But what about when one or more of your senses is heightened, changed, or even taken away all together? Do people with these radically-altered senses show us that each of us has limitless sensory potential, waiting to be unlocked? And is it possible that we have a mysterious "6th sense," one that is currently UnXplained?

Some of history's greatest tales are stories of escape, the most incredible of which defy explanation. How did Harry Houdini pull off his daring feats? Was the "Escape from Alcatraz" in fact, successful? And what about the mysterious guidance one man received that allowed him to escape the South Tower of the World Trade Center on 9/11? Are there strange forces these escapees draw upon to beat the odds, where so many others fail? Or, like a great magic trick, will the secrets of how they cheated captivity remain UnXplained?

Despite all of our modern technology and sophistication, there is much that we still don't know about what lies beneath our feet, deep underground. What is at the center of the Earth? Is there really a solid core of heavy metals, or could it be a hollow environment, as many researchers claim? And just how much of mankind's history took place underground? Recent discoveries of ancient underground structures such as the city of Derinkuyu and the Malta Hypogeum suggest that there may be more structures down there, waiting to be re-discovered. If much of our past was subterranean, could our future be as well?

On March 11th, 2020, the World Health Organization declared that the outbreak of the lethal Coronavirus had become a worldwide pandemic. We'll examine some of the most devastating plagues in human history, as well the scientific advances to combat these diseases, including the development of Edward Jenner's vaccine for smallpox in the 1790s. Jenner's vaccine was one of the first major breakthroughs in modern medicine and helped to end humanity's superstitious attitude towards disease. But in the future, might we face diseases that are different from the ones we've experienced in the past?

Stories of those who lead double lives are both daring and baffling. What compels a person to attempt to become someone else? Is it merely for material gain, to pull off an ingenious scam? Or is there a deeper reason? At one time or another, we've all fantasized about trying on a new identity, but when does the line between impersonation and transformation get blurred? Is it possible that by pretending to be someone else, a person can actually become that person, at least in their mind?

Mysterious disappearances are confounding and bizarre and simply can't be explained. Can these be chalked up to tragic accidents? Or could they be the result of something more...UnXplained?

Many believe it to be the Word of God, but others claim it contains inconsistencies and contradictions that could only be manmade.

For centuries, humanity has been compelled to build remarkable structures that are much more than simple places of shelter or work. What makes us want to create magnificent buildings that are bigger and grander than ourselves--and last for centuries? Whether it's Stonehenge, the Notre Dame Cathedral, or the world's tallest skyscrapers--extraordinary works of engineering are evidence of a strong instinct within us that we don't fully understand. Are we trying to prove something? Or perhaps show our power over nature? Or could there be another reason that is, for now...UnXplained?

Will we ever understand the motivations that drive people to undertake the most bizarre, intricate, and dangerous crimes -- or will the mind of a master criminal remain - UnXplained?

Throughout history, many have believed that certain places, things, or even people can be tainted with dark curses. Ominous lakes that morph into watery graves. Unlucky numbers that seem to cause bad things to happen. Paintings and precious stones, which bring death and destruction to their keepers. But can these mysterious curses really have the power to bring us harm? And if so, is it possible to understand their power, or will it remain UnXplained?

According to the Greek philosopher Plato, the lost continent of Atlantis was once home to an advanced civilization before it was destroyed in a cataclysm. But was Plato's story merely a myth? Or did Atlantis really exist? For centuries, archaeologists have tried to uncover evidence to prove that this legend is true. Will Atlantis finally be re-discovered, perhaps by employing modern technology? Or will this lost civilization remain...UnXplained?

From ancient civilizations to 20th century empires, mankind has had an inexplicable fascination with preserving the dead. But why? Are we simply too attached to the living to let them go? Or could it be that death isn't really the end, but rather a transition to a new beginning?

Gold. It's one of the most valuable precious metals on the planet, has been coveted by societies for centuries, and can be found inside countless modern electronics. Mankind's quest for gold harkens back thousands of years, but what is the special power that gold wields over our collective consciousness? Is it merely because it's rare and valuable, or could it be something more than that?

The total disregard for life exhibited by serial killers shocks our sense of humanity and makes us question our safety and security. These sadistic psychopaths rarely show any remorse or empathy for the lives they've destroyed. How could human beings be capable of these horrific atrocities? And what causes such a murderous defect in the human psyche?

Many see them as massive testaments to America's progress. Some view them as immutable symbols of the human spirit. Others perceive them as sacred shrines dedicated to the ideals of liberty and freedom. But no matter what they represent--America's monuments are inarguably impressive due to their colossal size and scope, their groundbreaking feats of engineering, and their storied histories. Why is it that America's greatest monuments continue to enthrall us decades--and sometimes centuries--after their creation? And perhaps more importantly, what closely guarded secrets may their implacable facades be hiding?

For centuries, legends and eyewitness accounts have told of a massive, hairy creature that roams the forest on two legs. While science has yet to prove the existence of this mythical man-beast, countless researchers and experiencers around the world are convinced that there is a giant, ape-like animal hiding in remote parts of the world. They point to the discovery of large, inexplicable footprints as evidence of the so-called "Bigfoot" that they hope to prove is real. But does Bigfoot actually exist?