Host Giorgio Tsoukalos probes the series archives to present the most compelling UFO SIGHTINGS.

The world's most famous painting vanishes in a daring heist, sparking international outrage and a global manhunt.

Deadly anthrax spores sent through the mail kill five people and spread authorities thin; the FBI works around the clock to stop this brazen act of bioterrorism, but the letters keep coming.

Host Giorgio Tsoukalos probes the series archives to present the most compelling UFO SIGHTINGS.

Nicola Tesla had revolutionary ideas, but in the hands of the wrong people, those ideas could be used for evil purposes; when Tesla died, he allegedly had 80 trunks of papers full of ideas, but only 60 have been seen again.

On September 11, 2001, the world watched the attacks on the World Trade Center unfold from the outside; we reveal what people inside the buildings saw and heard as events unfolded around them, and they raced to survive.

Turned down for a future position at home, Charles is so irate he refuses to talk to anyone in the unit.

The oppressive Korean heat gets to everyone, especially Klinger.

Mike restores a 1968 Beaumont for a charity auction, but scrambles to save the build and the fundraiser when his budget is pulled out from under him; Avery steals a Rust Bros client with a German-made Unimog, putting his friendship with Mike at risk.

While Kevin works on his breakwater at Hook Bay, Erik gets to work on the Pipe Dream; the mill hosts a group of high school students interested in learning how the business works.

As Matt and his team chase the elusive one that got away, they risk getting in over their heads, literally, as an extraction nearly sinks their whole trip.

Mike restores a 1968 Beaumont for a charity auction, but scrambles to save the build and the fundraiser when his budget is pulled out from under him; Avery steals a Rust Bros client with a German-made Unimog, putting his friendship with Mike at risk.

While Kevin works on his breakwater at Hook Bay, Erik gets to work on the Pipe Dream; the mill hosts a group of high school students interested in learning how the business works.

Strange beetles and butterflies are mailed into Canada that may carry disease.

A captain navigates troubled waters when he forgets to declare himself to the authorities.

A strong windstorm affects the members of the 4077th in various ways.

Charles assumes heroic proportions after reviving a dying patient with heart massage.

From the strict, brutal codes of Hammurabi and the Samurai to the secretly malevolent evil eye and Voodoo dolls, history is full of stories of acts committed in the name of revenge.

A look at the possibility of structures like the Men-an-Tol monolith or the colossal Olmec being imbued with mystical powers.

A Revolutionary War era ship hides under the streets of Manhattan; a sprawling Roman villa is unearthed in the backyard of an English home; finding an ancient Grecian maze that is long thought to be a myth.

A species thought lost forever is spotted again; a dog plays an unexpected role in recovering the World Cup trophy; a puppy from the Ice Age emerges intact after 18,000 years; revealing just how unpredictable the natural world can be.

A strong windstorm affects the members of the 4077th in various ways.

Charles assumes heroic proportions after reviving a dying patient with heart massage.

From the strict, brutal codes of Hammurabi and the Samurai to the secretly malevolent evil eye and Voodoo dolls, history is full of stories of acts committed in the name of revenge.

Deadly anthrax spores sent through the mail kill five people and spread authorities thin; the FBI works around the clock to stop this brazen act of bioterrorism, but the letters keep coming.

Host Giorgio Tsoukalos probes the series archives to present the most compelling UFO SIGHTINGS.

A husband's homemade bandage, a college dropout's breakthrough adhesive and a factory worker's wartime fix transform simple strips of tape into indispensable American icons, creating a $90 billion industry, one sticky invention at a time.

If size counts, these machines rewrite all the rules; Dolph Lundgren gets up close inside legendary giants: the Antonov An-225 cargo jet, history's largest aircraft; the 200-ton WWII Maus tank designed by Porsche for Hitler, the largest ever made.

A species thought lost forever is spotted again; a dog plays an unexpected role in recovering the World Cup trophy; a puppy from the Ice Age emerges intact after 18,000 years; revealing just how unpredictable the natural world can be.

A husband's homemade bandage, a college dropout's breakthrough adhesive and a factory worker's wartime fix transform simple strips of tape into indispensable American icons, creating a $90 billion industry, one sticky invention at a time.

If size counts, these machines rewrite all the rules; Dolph Lundgren gets up close inside legendary giants: the Antonov An-225 cargo jet, history's largest aircraft; the 200-ton WWII Maus tank designed by Porsche for Hitler, the largest ever made.

A species thought lost forever is spotted again; a dog plays an unexpected role in recovering the World Cup trophy; a puppy from the Ice Age emerges intact after 18,000 years; revealing just how unpredictable the natural world can be.

A Revolutionary War era ship hides under the streets of Manhattan; a sprawling Roman villa is unearthed in the backyard of an English home; finding an ancient Grecian maze that is long thought to be a myth.

A look at the possibility of structures like the Men-an-Tol monolith or the colossal Olmec being imbued with mystical powers.

A strong windstorm affects the members of the 4077th in various ways.

Charles assumes heroic proportions after reviving a dying patient with heart massage.

Mike converts a 1957 GMC truck to run on alcohol for a truck-obsessed teenage girl; Avery goes the extra mile, finishing the Unimog for its hard-to-please owner.

Kevin is on a.

While searching for abandoned relics along The Alaska Highway, Matt's team steps up as car hunters in their own right.

Mike converts a 1957 GMC truck to run on alcohol for a truck-obsessed teenage girl; Avery goes the extra mile, finishing the Unimog for its hard-to-please owner.

Kevin is on a.

An American arrives at customs with firearms; a traveler makes a breathtaking statement.

An irritated traveler pushes officers to the limit; Haitian fruits may contain more than vitamins.

Charles becomes the most unpopular man in camp when he receives a winterized polar suit from his parents.

The experiences of being wounded, flown to the 4077th, operated on and treated are seen through a soldier's eyes.

The modern concept of extreme sports is a product of marketing, but back in the old days, the lack of rules made them truly extreme; from bone-crushing football and deadly baseball games to wild events like auto polo.

From ancient war machines to devastating weapons of mass destruction, these are the innovations that changed warfare and rank among history's deadliest.

During World War II, the Nazi war machine creates specialized death camps; at Sobibor, in Poland, a small group of Jews engineer a mass escape and help bring the story of the Holocaust to the rest of the world.

A German American pilot, Dieter Dengler, uses survival skills honed as a child to escape a secret prison in Laos during the early years of the Vietnam War.

Charles becomes the most unpopular man in camp when he receives a winterized polar suit from his parents.

The experiences of being wounded, flown to the 4077th, operated on and treated are seen through a soldier's eyes.

From ancient war machines to devastating weapons of mass destruction, these are the innovations that changed warfare and rank among history's deadliest.

A husband's homemade bandage, a college dropout's breakthrough adhesive and a factory worker's wartime fix transform simple strips of tape into indispensable American icons, creating a $90 billion industry, one sticky invention at a time.

If size counts, these machines rewrite all the rules; Dolph Lundgren gets up close inside legendary giants: the Antonov An-225 cargo jet, history's largest aircraft; the 200-ton WWII Maus tank designed by Porsche for Hitler, the largest ever made.

A century ago, the cookie industry didn't exist, until a wave of innovators turned it into a $15 billion powerhouse.

Remember when people would do just about anything for an adrenaline fix?; revisit the ways people once chased a thrill; these stunts and gravity-pushing spectacles didn't always stick the landing, but that didn't stop anyone from trying.

From ancient war machines to devastating weapons of mass destruction, these are the innovations that changed warfare and rank among history's deadliest.

A century ago, the cookie industry didn't exist, until a wave of innovators turned it into a $15 billion powerhouse.

Remember when people would do just about anything for an adrenaline fix?; revisit the ways people once chased a thrill; these stunts and gravity-pushing spectacles didn't always stick the landing, but that didn't stop anyone from trying.

The modern concept of extreme sports is a product of marketing, but back in the old days, the lack of rules made them truly extreme; from bone-crushing football and deadly baseball games to wild events like auto polo.

During World War II, the Nazi war machine creates specialized death camps; at Sobibor, in Poland, a small group of Jews engineer a mass escape and help bring the story of the Holocaust to the rest of the world.

A German American pilot, Dieter Dengler, uses survival skills honed as a child to escape a secret prison in Laos during the early years of the Vietnam War.

Charles becomes the most unpopular man in camp when he receives a winterized polar suit from his parents.

The experiences of being wounded, flown to the 4077th, operated on and treated are seen through a soldier's eyes.

Mike sells a Willys Jeep to custom car wizard James West, but the price will be determined by the winner of a drag race; the challenge puts pressure on both shops to produce competition-worthy trucks.

With the battle for logs taking a toll, Kevin keeps pursuing his plans to build the Pipe Dream and a new saw at the mill; mill hand Simon's plans for a logger sports day get wildly out of hand once Kevin steps in to help.

Matt's team is hunting 1950s Volkswagens by any means necessary, even scaling a ravine or craning over treetops.

Mike sells a Willys Jeep to custom car wizard James West, but the price will be determined by the winner of a drag race; the challenge puts pressure on both shops to produce competition-worthy trucks.

With the battle for logs taking a toll, Kevin keeps pursuing his plans to build the Pipe Dream and a new saw at the mill; mill hand Simon's plans for a logger sports day get wildly out of hand once Kevin steps in to help.

Packaged sweets at JFK Airport; a Dutch visitor travels stateside; mistaken identity for a traveler in Washington State; party girls' plans are deflated.

Officers don't believe a traveler's claims; a Canadian traveler is upset; clearance issues for a package from China.

Hawkeye and B.J. discover Charles living the life of Riley due to the attentions of his menially paid Korean servant.

Heavy casualties nearly exhaust the unit's supply of Pentothal.

Two pizza juggernauts expand their empires as a new contender turns the fight into a three-way race to become America's big pizza chain.

From a first-century Roman emperor who created an early version of the whoopee cushion to modern materials that emulate human body fluids, gross equals big bucks for toymakers; examining innovative toys designed to shock.

From the velocipede to the Schwinn Stingray, or even pedal cars to Power Wheels, viewers will roll their way through the history of the hottest toys on wheels and the surprising stories behind their creations.

As toys became increasingly complex in the early 1970s, two unconventional inventors risk their homes and careers to bring revolutionary twists to classic games; together, Uno and Connect Four unleash a wave of family-friendly games.

During WWII, a struggling automaker and Detroit's industry titan race to build a revolutionary all-purpose military vehicle, then spend decades battling to reinvent their wartime creation into America's popular type of car, the SUV.

Hawkeye and B.J. discover Charles living the life of Riley due to the attentions of his menially paid Korean servant.

Heavy casualties nearly exhaust the unit's supply of Pentothal.

Two pizza juggernauts expand their empires as a new contender turns the fight into a three-way race to become America's big pizza chain.

A century ago, the cookie industry didn't exist, until a wave of innovators turned it into a $15 billion powerhouse.

Remember when people would do just about anything for an adrenaline fix?; revisit the ways people once chased a thrill; these stunts and gravity-pushing spectacles didn't always stick the landing, but that didn't stop anyone from trying.

Four bladesmiths must forge a blade with not one, but two Damascus billets.

From blasting through mountains, to building gigantic infrastructure across the sea, to the biggest battleship in history and iconic builds like the Pentagon and the Maginot Line, WWII engineering is a battle of scale that turns the tide of the war.

Two pizza juggernauts expand their empires as a new contender turns the fight into a three-way race to become America's big pizza chain.

Four bladesmiths must forge a blade with not one, but two Damascus billets.

From blasting through mountains, to building gigantic infrastructure across the sea, to the biggest battleship in history and iconic builds like the Pentagon and the Maginot Line, WWII engineering is a battle of scale that turns the tide of the war.

From a first-century Roman emperor who created an early version of the whoopee cushion to modern materials that emulate human body fluids, gross equals big bucks for toymakers; examining innovative toys designed to shock.

From the velocipede to the Schwinn Stingray, or even pedal cars to Power Wheels, viewers will roll their way through the history of the hottest toys on wheels and the surprising stories behind their creations.

As toys became increasingly complex in the early 1970s, two unconventional inventors risk their homes and careers to bring revolutionary twists to classic games; together, Uno and Connect Four unleash a wave of family-friendly games.

During WWII, a struggling automaker and Detroit's industry titan race to build a revolutionary all-purpose military vehicle, then spend decades battling to reinvent their wartime creation into America's popular type of car, the SUV.

Hawkeye and B.J. discover Charles living the life of Riley due to the attentions of his menially paid Korean servant.

Heavy casualties nearly exhaust the unit's supply of Pentothal.

Rust Valley rivals face off in the Shop Truck Challenge; Mike struggles to restore a 1971 Chevy Blazer for a wedding day surprise; Avery's plan to repurpose a military truck for music festivals hits a sour note.

The Seacrest finally hits the water, but the building of the Pipe Dream requires all hands on deck; a guitar maker comes to Kevin in search of unique wood; Sarah goes on a mission to find a dress for Jack's wedding.

As if the car hunt wasn't tough enough, Matt and his team head East to search for classic pickup trucks in unfamiliar territory.

Rust Valley rivals face off in the Shop Truck Challenge; Mike struggles to restore a 1971 Chevy Blazer for a wedding day surprise; Avery's plan to repurpose a military truck for music festivals hits a sour note.

The Seacrest finally hits the water, but the building of the Pipe Dream requires all hands on deck; a guitar maker comes to Kevin in search of unique wood; Sarah goes on a mission to find a dress for Jack's wedding.

A traveler returns from Colombia with a lot of luggage; a pregnant passenger in Detroit; a package from India is halted; a traveler is Washington is questioned.

An auto theft arrest in Detroit; dozens of vials in the JFK Mail Facility; an American traveler has reptiles; a traveler in New York shows signs of smuggling; a family reunites in Detroit.

Father Mulcahy takes being passed over for a promotion philosophically until he hears of a heroic helicopter pilot's advancement.

Father Mulcahy writes a pre-Christmas letter home to his sister.

From the kitchen to the battlefield, some machines are just too strange to believe; like an appliance that runs on pup power; or a mousetrap so deadly, you need a permit to own one; how about a submarine car straight out of a Bond movie?

Isolated along the southernmost part of the planet, Antarctica is best known as the frozen continent.

Analyzing if monsters exist, creatures who lurk in dense forests or fly over large cities; for centuries, monsters like Mothman, the Thunderbird, and Bigfoot have mystified witnesses, skeptics, and scientists alike.

An exploration of the world's most fascinating, strange and inexplicable mysteries; compelling contributions from scientists, historians, and witnesses.

Father Mulcahy takes being passed over for a promotion philosophically until he hears of a heroic helicopter pilot's advancement.

Father Mulcahy writes a pre-Christmas letter home to his sister.

Isolated along the southernmost part of the planet, Antarctica is best known as the frozen continent.

Host Giorgio Tsoukalos explores the series archives to investigate mysterious moments that just might contain an extraterrestrial connection.

From the kitchen to the battlefield, some machines are just too strange to believe; like an appliance that runs on pup power; or a mousetrap so deadly, you need a permit to own one; how about a submarine car straight out of a Bond movie?

Every year, people risk their lives to enter places the world has marked off-limits, and in most cases, no one fully understands why.

Some rescues read like Hollywood - except they were real; in Operation Halyard, villagers and resistance fighters built an airstrip by hand to spirit stranded airmen out of Nazi territory.

The team runs a new test in the Mesa that produces loud and clear evidence of buried metallic objects; a new aerial experiment yields solid clues about a giant force field in the middle of Skinwalker Ranch.

Every year, people risk their lives to enter places the world has marked off-limits, and in most cases, no one fully understands why.

Some rescues read like Hollywood - except they were real; in Operation Halyard, villagers and resistance fighters built an airstrip by hand to spirit stranded airmen out of Nazi territory.

Isolated along the southernmost part of the planet, Antarctica is best known as the frozen continent.

Analyzing if monsters exist, creatures who lurk in dense forests or fly over large cities; for centuries, monsters like Mothman, the Thunderbird, and Bigfoot have mystified witnesses, skeptics, and scientists alike.

An exploration of the world's most fascinating, strange and inexplicable mysteries; compelling contributions from scientists, historians, and witnesses.

Father Mulcahy takes being passed over for a promotion philosophically until he hears of a heroic helicopter pilot's advancement.

Father Mulcahy writes a pre-Christmas letter home to his sister.

Al has a mishap on the runway; Joe gets an old snow plane running; the boys are stuck in Turkey with a water bomber.

Devan encounters gear difficulties when he transports a DC-3 across the country; frigid weather creates problems at Buffalo Airways.

Finally back up on the mountain, Kevin hauls as much red cedar as he can; Sarah helps with a massive reforestation effort and gets Kevin to create a custom wooden table for a client in California.

Al has a mishap on the runway; Joe gets an old snow plane running; the boys are stuck in Turkey with a water bomber.

Devan encounters gear difficulties when he transports a DC-3 across the country; frigid weather creates problems at Buffalo Airways.

Hidden dangers once held at bay by humans erupt with force, from everyday objects ready to explode to chemical plants and locust plagues; as nature and human legacy collide, these ticking time bombs threaten to send the world up in smoke.

Rome is a young, aggressive republic, but the Empire is shaped by decades of battle against Carthage and driven by the ambition of its leaders and ruthless generals.

When the Roman Empire is the most powerful it has ever been, Germanic invasions, the plague and a new leader plunges Rome into chaos, divided into two factions which causes a decline Rome cannot recover from.

From soaring skyscrapers like One World Trade Center to impenetrable vaults like Fort Knox, humanity's strongest structures were engineered to defy disaster; but in a world without people, even the mightiest begin to crack.

In a world without humans, the deserts once tamed rise to reclaim great triumphs: from Las Vegas to Dubai's Burj Khalifa; as sand, salt, and sun dismantle cities, the wastelands quietly take back the ground borrowed.

When humanity vanishes, the vast and fragile infrastructure hidden underground-from subways and pipelines to one of the big coal seams in the United States-begins to unravel.

In the absence of humanity, the world's cities like New York, Orlando and Rio de Janeiro are reclaimed by nature, as forests rise, animals roam free and fire and flood undo centuries of construction.

After humanity ceases to exist, the homes we built from suburban mansions and Miami condos to rural farmhouses face a relentless siege by fire, flood, wildlife and time.

Hidden dangers once held at bay by humans erupt with force, from everyday objects ready to explode to chemical plants and locust plagues; as nature and human legacy collide, these ticking time bombs threaten to send the world up in smoke.

From soaring skyscrapers like One World Trade Center to impenetrable vaults like Fort Knox, humanity's strongest structures were engineered to defy disaster; but in a world without people, even the mightiest begin to crack.

In a world without humans, the deserts once tamed rise to reclaim great triumphs: from Las Vegas to Dubai's Burj Khalifa; as sand, salt, and sun dismantle cities, the wastelands quietly take back the ground borrowed.

When humanity vanishes, the vast and fragile infrastructure hidden underground-from subways and pipelines to one of the big coal seams in the United States-begins to unravel.

In the absence of humanity, the world's cities like New York, Orlando and Rio de Janeiro are reclaimed by nature, as forests rise, animals roam free and fire and flood undo centuries of construction.

After humanity ceases to exist, the homes we built from suburban mansions and Miami condos to rural farmhouses face a relentless siege by fire, flood, wildlife and time.

Hidden dangers once held at bay by humans erupt with force, from everyday objects ready to explode to chemical plants and locust plagues; as nature and human legacy collide, these ticking time bombs threaten to send the world up in smoke.

From soaring skyscrapers like One World Trade Center to impenetrable vaults like Fort Knox, humanity's strongest structures were engineered to defy disaster; but in a world without people, even the mightiest begin to crack.

Mike and Jersey trip out over an Oddfellow's Lodge in Maryland, and visit one man's combination theme park, art installation and roadside attraction.

Mike fixes a 1961 Cadillac to showcase and smash to pieces at Rust Valley's annual Demolition Derby; mechanic Dave enters a 1974 Chrysler New Yorker for the big event.

Mike restores a 1938 International Harvester; the shop holds a swap meet; wedding bells ring for Greg.

Dave and his daughter Alyssa struggle to recover a vintage ore cart from an abandoned copper mine; Angela struggles on what should be an easy job, and Dale goes on an epic hunt for furnace oil for Donny's shop.

Mike fixes a 1961 Cadillac to showcase and smash to pieces at Rust Valley's annual Demolition Derby; mechanic Dave enters a 1974 Chrysler New Yorker for the big event.

Mike restores a 1938 International Harvester; the shop holds a swap meet; wedding bells ring for Greg.

Remember when people would do just about anything for an adrenaline fix?; revisit the ways people once chased a thrill; these stunts and gravity-pushing spectacles didn't always stick the landing, but that didn't stop anyone from trying.

If size counts, these machines rewrite all the rules; Dolph Lundgren gets up close inside legendary giants: the Antonov An-225 cargo jet, history's largest aircraft; the 200-ton WWII Maus tank designed by Porsche for Hitler, the largest ever made.

Deadly anthrax spores sent through the mail kill five people and spread authorities thin; the FBI works around the clock to stop this brazen act of bioterrorism, but the letters keep coming.

These are the stories of history's most unusual pastimes, some fascinating, some dangerous, but each of them completely unbelievable.

Some rescues read like Hollywood - except they were real; in Operation Halyard, villagers and resistance fighters built an airstrip by hand to spirit stranded airmen out of Nazi territory.

Three smiths hope to cash in when they are given the opportunity to win money after each challenge; after two tough rounds, all three smiths head back to their home forge to recreate the serrated Dussage.

A century ago, the cookie industry didn't exist, until a wave of innovators turned it into a $15 billion powerhouse.

Deadly anthrax spores sent through the mail kill five people and spread authorities thin; the FBI works around the clock to stop this brazen act of bioterrorism, but the letters keep coming.

Remember when people would do just about anything for an adrenaline fix?; revisit the ways people once chased a thrill; these stunts and gravity-pushing spectacles didn't always stick the landing, but that didn't stop anyone from trying.

If size counts, these machines rewrite all the rules; Dolph Lundgren gets up close inside legendary giants: the Antonov An-225 cargo jet, history's largest aircraft; the 200-ton WWII Maus tank designed by Porsche for Hitler, the largest ever made.

From a family surviving two direct lightning strikes to a woman pulled alive from a submerged car with all its doors and windows sealed, extraordinary survival stories are being captured on camera around the world.

As the team begins a large-scale drilling operation to uncover a possible metal object in the Mesa, they launch a swarm of one hundred drones that reveals a major answer about the mystery of the Bubble.

Matty raises compelling questions about the team's revealing new experiment in the Bubble boundary.

Remember when people would do just about anything for an adrenaline fix?; revisit the ways people once chased a thrill; these stunts and gravity-pushing spectacles didn't always stick the landing, but that didn't stop anyone from trying.

As the team begins a large-scale drilling operation to uncover a possible metal object in the Mesa, they launch a swarm of one hundred drones that reveals a major answer about the mystery of the Bubble.

Matty raises compelling questions about the team's revealing new experiment in the Bubble boundary.

Some rescues read like Hollywood - except they were real; in Operation Halyard, villagers and resistance fighters built an airstrip by hand to spirit stranded airmen out of Nazi territory.

Deadly anthrax spores sent through the mail kill five people and spread authorities thin; the FBI works around the clock to stop this brazen act of bioterrorism, but the letters keep coming.

If size counts, these machines rewrite all the rules; Dolph Lundgren gets up close inside legendary giants: the Antonov An-225 cargo jet, history's largest aircraft; the 200-ton WWII Maus tank designed by Porsche for Hitler, the largest ever made.

These are the stories of history's most unusual pastimes, some fascinating, some dangerous, but each of them completely unbelievable.

A Rust Valley road trip steers Mike into the danger zone after Connor gives him an ultimatum: buy another car and Connor will blow up one from the Field of Dreams.

Tempers flare as Kevin and his team finalize building the Pipe Dream and finally get the boat out on the water; with the snow finally gone, the crew heads back up the mountain to yard wood; Kevin has a special surprise for Jack and Rachel's wedding.

Tension grows among the team as they try to fill the trailer with pre-war vehicles across railway ghost towns.

A Rust Valley road trip steers Mike into the danger zone after Connor gives him an ultimatum: buy another car and Connor will blow up one from the Field of Dreams.

Tempers flare as Kevin and his team finalize building the Pipe Dream and finally get the boat out on the water; with the snow finally gone, the crew heads back up the mountain to yard wood; Kevin has a special surprise for Jack and Rachel's wedding.

JFK Airport officials look for drugs in backpacks; a driver in Washington arrives in someone else's vehicle; a Detroit citizen takes a wrong turn.

The canine unit uncovers trouble in Michigan; blood-stained baggage in Detroit; officers are suspicious of a Canadian citizen.

B.J. becomes a surrogate father to a Korean family when the young daughter seeks medical assistance for her father.

Hawkeye falls for a Swedish doctor who arrives at the 4077th to observe combat surgery.

On Sept. 11, 2001, an act of terror changes America; Mastermind Osama bin Laden threatens further attacks; a global manhunt begins; almost a decade later, U.S. Navy SEALs raid a compound in Abbottabad, Pakistan and kill him.

Pablo Escobar, the narco-trafficker who single-handedly supplied most of America's cocaine in the 1980s, had billions of dollars in cash; by the time he was gunned down in 1993, it's believed he was worth over $50 billion in today's money.

Counting down ten unexplainable technologies in history, from mysterious golden orbs discovered in Mexico and a sacred wooden box that could communicate with the heavens to an ancient tomb that is said to depict an astronaut.

For more than four decades, award-winning journalist Linda Moulton Howe has covered the most mysterious phenomena on Earth.

B.J. becomes a surrogate father to a Korean family when the young daughter seeks medical assistance for her father.

Hawkeye falls for a Swedish doctor who arrives at the 4077th to observe combat surgery.

On Sept. 11, 2001, an act of terror changes America; Mastermind Osama bin Laden threatens further attacks; a global manhunt begins; almost a decade later, U.S. Navy SEALs raid a compound in Abbottabad, Pakistan and kill him.

From a family surviving two direct lightning strikes to a woman pulled alive from a submerged car with all its doors and windows sealed, extraordinary survival stories are being captured on camera around the world.

As the team begins a large-scale drilling operation to uncover a possible metal object in the Mesa, they launch a swarm of one hundred drones that reveals a major answer about the mystery of the Bubble.

As one renowned military leader, his conquests were so decisive that some believed he was descended from the gods; at only 32, with an empire that was expanding, Alexander the Great died unexpectedly; what, or who, is responsible for his death?

Examining how researchers use artificial intelligence to analyze historical data and evaluate claims of extraterrestrial activity.

On Sept. 11, 2001, an act of terror changes America; Mastermind Osama bin Laden threatens further attacks; a global manhunt begins; almost a decade later, U.S. Navy SEALs raid a compound in Abbottabad, Pakistan and kill him.

As one renowned military leader, his conquests were so decisive that some believed he was descended from the gods; at only 32, with an empire that was expanding, Alexander the Great died unexpectedly; what, or who, is responsible for his death?

Examining how researchers use artificial intelligence to analyze historical data and evaluate claims of extraterrestrial activity.

Pablo Escobar, the narco-trafficker who single-handedly supplied most of America's cocaine in the 1980s, had billions of dollars in cash; by the time he was gunned down in 1993, it's believed he was worth over $50 billion in today's money.

Counting down ten unexplainable technologies in history, from mysterious golden orbs discovered in Mexico and a sacred wooden box that could communicate with the heavens to an ancient tomb that is said to depict an astronaut.

For more than four decades, award-winning journalist Linda Moulton Howe has covered the most mysterious phenomena on Earth.

B.J. becomes a surrogate father to a Korean family when the young daughter seeks medical assistance for her father.

Hawkeye falls for a Swedish doctor who arrives at the 4077th to observe combat surgery.

Old rivalries bring new alliances as Rust Valley's competing shops get ready to face off at the annual Hit-to-Pass race; the cost of Avery's Deuce-and-a-Half music truck spirals out of control.

Big Donny's senior drivers battle each other in the far north, while his most junior races to a hydro plant that can't restore power without her; when a competitor ups his game, Donny discovers his hotshotting empire is under attack.

Matt's final mission is for all thing's fast; the team hunts down muscle cars and racing legends to preserve priceless history.

Old rivalries bring new alliances as Rust Valley's competing shops get ready to face off at the annual Hit-to-Pass race; the cost of Avery's Deuce-and-a-Half music truck spirals out of control.

Big Donny's senior drivers battle each other in the far north, while his most junior races to a hydro plant that can't restore power without her; when a competitor ups his game, Donny discovers his hotshotting empire is under attack.

A traveler with a questionable past; contraband in the mail facility; officers inspect passengers at JFK; a fugitive shows up.

An inside smuggling job is revealed at JFK; a wrong turn separates friends; German tourists in Washington; a baggage exam in Detroit.

Col. Potter's mare, Sophie, mysteriously disappears from her corral; Hawkeye and B.J. try to help a young Korean.

A young surgeon from Tokyo makes the doctors of the 4077th feel out of touch with new medical practices.

Legendary beasts are believed to roam the earth and the seas, terrorizing, killing, and even possessing humans; but are these creatures merely metaphors or is there proof they've actually been unleashed to wreak havoc?

Age-old mysterious ruins stand as silent sentinels from the past, with their true history seemingly erased by time; modern archaeology attempts to unravel the enigma of how and why the ancient structures were built.

From a mythical monster that turns out to be real, to a deadly prehistoric animal, and a frozen tundra hiding a pandora's box full of lethal pathogens, these startling discoveries shock and terrify the world.

History's biggest discoveries aren't always its best.

Col. Potter's mare, Sophie, mysteriously disappears from her corral; Hawkeye and B.J. try to help a young Korean.

A young surgeon from Tokyo makes the doctors of the 4077th feel out of touch with new medical practices.

Legendary beasts are believed to roam the earth and the seas, terrorizing, killing, and even possessing humans; but are these creatures merely metaphors or is there proof they've actually been unleashed to wreak havoc?

As one renowned military leader, his conquests were so decisive that some believed he was descended from the gods; at only 32, with an empire that was expanding, Alexander the Great died unexpectedly; what, or who, is responsible for his death?

Examining how researchers use artificial intelligence to analyze historical data and evaluate claims of extraterrestrial activity.

A down-on-his-luck mechanic transforms outlaw moonshine racing into a major American spectator sport, overcoming rivals, setbacks, and financial crises to build a billion-dollar sports empire.

Dolph Lundgren pulls the curtain back on the shadowy devices that won secret wars, the CIA's pigeon-mounted spy cameras, bone-conduction radios hidden inside tobacco pipes, the silent heart attack gun and the secret Enigma code that changed WWII.

History's biggest discoveries aren't always its best.

A down-on-his-luck mechanic transforms outlaw moonshine racing into a major American spectator sport, overcoming rivals, setbacks, and financial crises to build a billion-dollar sports empire.

Dolph Lundgren pulls the curtain back on the shadowy devices that won secret wars, the CIA's pigeon-mounted spy cameras, bone-conduction radios hidden inside tobacco pipes, the silent heart attack gun and the secret Enigma code that changed WWII.

History's biggest discoveries aren't always its best.

From a mythical monster that turns out to be real, to a deadly prehistoric animal, and a frozen tundra hiding a pandora's box full of lethal pathogens, these startling discoveries shock and terrify the world.

Age-old mysterious ruins stand as silent sentinels from the past, with their true history seemingly erased by time; modern archaeology attempts to unravel the enigma of how and why the ancient structures were built.

Col. Potter's mare, Sophie, mysteriously disappears from her corral; Hawkeye and B.J. try to help a young Korean.

A young surgeon from Tokyo makes the doctors of the 4077th feel out of touch with new medical practices.

Rust Valley's auto shops battle it out at the high-impact Hit to Pass drag race. But when one competitor is accused of cheating, the brawl moves from the track to the pit.

Big Donny dispatches his entire crew to a challenging roadside crash recovery, but things go sideways when Craig is missing-in-action on the job. Angela struggles when she's sidelined after her truck breaks down on a hotshot mission.

The team tracks down several historic vehicles in the remote region of Rainy River, in Northwestern Ontario; as Steve and Lee compete with Dave, Matt and Jess hit the skies in search of a historic railway truck to assist a local museum.

Rust Valley's auto shops battle it out at the high-impact Hit to Pass drag race. But when one competitor is accused of cheating, the brawl moves from the track to the pit.

Big Donny dispatches his entire crew to a challenging roadside crash recovery, but things go sideways when Craig is missing-in-action on the job. Angela struggles when she's sidelined after her truck breaks down on a hotshot mission.

An inside smuggling job is revealed at JFK; a wrong turn separates friends; German tourists in Washington; a baggage exam in Detroit.

Canines in Chicago sniff out cash; a Canadian vehicle is seedy; officers discover a traveler's alter ego; officers sift through suspicious leaves.

Radar falls in love; Margaret celebrates her divorce.

The 4077th's evacuation to a nearby cave poses a big problem for Hawkeye, then Col. Potter becomes aware of it.

Exploding cars and blimp disasters to kids sent through the mail and doomed personal helicopters; the past is packed with travel tales and the misfires that paved the road to modern transportation.

From doomed voyages across continents and oceans to covert CIA operations, these missions show that no matter how much preparation and planning are done, things can still turn deadly.

During the Civil War, a daring prison break frees hundreds of captured Union soldiers; Colonel Thomas Rose was a schoolteacher before the Civil War; when he was captured and sent to Libby Prison in Richmond Virginia, he engineers a mass escape.

Petty thief Rene Belbenoit is captured and sentenced to hard time at France's notorious penal colony in French Guiana; he is determined to escape or die trying, and his story becomes the basis of several popular movies in Hollywood.

Radar falls in love; Margaret celebrates her divorce.

The 4077th's evacuation to a nearby cave poses a big problem for Hawkeye, then Col. Potter becomes aware of it.