Mariana delves into a new scheme called sextortion, where compromising photos are used to extort victims; while searching for the scammer who targeted a young American, she uncovers a scam culture even more terrifying than she had imagined.

Will travels deep into the Amazon in search of a giant green anaconda.

Will heads to the Himalayas in search of the secret to happiness.

Mariana tracks the illicit path of hashish from Morocco into Europe; a world of shadowy dealers, fast smuggling boats and endless wealth.

Health care costs have pushed millions of Americans to the black market.

Mariana goes inside the dangerous, high-stakes world of illegal gambling to try and understand its allure, its growth and its dark side.

Mariana heads to the Congo to investigate the illegal trading of wild apes that has apes on the brink of extinction.

A businesswoman's personal items sound alarms; a cargo ship crew member who has been concealing in the ceiling; a puppeteer couple; an American seeking legal advice in Ontario.

Partygoers receive rave reviews at the Coutts crossing; officers delve into an international affair.

Cookies can be more trouble than treat; twins with matching beers take a wrong turn.

Officers make a stunning discovery; a tourist's papers hint at her true plans for coming to Canada.

Lisa has to decide help a competitor push further into the arctic unknown or go back to Polar headquarters with her teammates.

Ken uncovers a mother lode of gold after he changes the Beast's location; breakdowns threaten to bring an early end to Bernie's season; Big Al selects a final site for his sluice plant.

An 84-year-old collector in Balzac, Alberta has a property jam-packed with odd artifacts.

A businesswoman's personal items sound alarms; a cargo ship crew member who has been concealing in the ceiling; a puppeteer couple; an American seeking legal advice in Ontario.

Partygoers receive rave reviews at the Coutts crossing; officers delve into an international affair.

Cookies can be more trouble than treat; twins with matching beers take a wrong turn.

Officers make a stunning discovery; a tourist's papers hint at her true plans for coming to Canada.

Alaska's next generation must respect the land and its inhabitants to survive.

The next generation of remote Alaskans must secure food in bleak winter.

The team is in the crystal-clear waters of Bimini in the Bahamas to witness the incredible journey of the great hammerhead shark; as the team follows the shark's migration, they discover the secrets of how these animals navigate the vast ocean.

The team travels to the Dominican Republic in the Caribbean to reveal the greatest secrets in the lives of the North Atlantic humpback whale; they witness a mother defend her calf in the ultimate ocean battle with a pack of orcas.

The team is in the Azores to tag the sixgill shark and learn more about its nightly patterns hunting for food in the abyss; the team tags and retrieves valuable data, uncovering why this shark undertakes its epic journey from the depths at night.

In the Azores, the team follows the elusive sperm whales to their hunting grounds a mile beneath the surface, where they discover the secret lives of these deep-diving whales.

Learning how a population of bowhead whales, once hunted almost to extinction, is faring today; the team is the first to observe the feeding strategies of the deep-sea Greenland shark, an animal that can live for more than 400 years.

The team's mission is to figure out if Svalbard's polar bears are adapting to their environment; they face this giant of the Arctic Ocean and scale a glacier to learn how much time is left for one of the most critical habitats for polar bears.

A 40th-anniversary gift, $1,500 in cash and a stuffed jewelry box get lost.

The students start the dogfighting phase to learn how to attack.

The team's mission is to figure out if Svalbard's polar bears are adapting to their environment; they face this giant of the Arctic Ocean and scale a glacier to learn how much time is left for one of the most critical habitats for polar bears.

A 40th-anniversary gift, $1,500 in cash and a stuffed jewelry box get lost.

The students start the dogfighting phase to learn how to attack.

Alaska's next generation must respect the land and its inhabitants to survive.

The next generation of remote Alaskans must secure food in bleak winter.

The team is in the crystal-clear waters of Bimini in the Bahamas to witness the incredible journey of the great hammerhead shark; as the team follows the shark's migration, they discover the secrets of how these animals navigate the vast ocean.

The team travels to the Dominican Republic in the Caribbean to reveal the greatest secrets in the lives of the North Atlantic humpback whale; they witness a mother defend her calf in the ultimate ocean battle with a pack of orcas.

A senior has some unfriendly gear in his RV; a Canadian returning from Panama tells all.

An American is busted trying to catch a different kind of trip; officers help a tipsy traveler.

A heavy automobile container hints at trouble; A student's stash of food brings him discomfort.

A traveler returns with a surprise; Marine officers come upon an infested container.

Experts predict one of the shortest and warmest winters on record; as a result, companies risk financial ruin and communities face deprivation unless the drivers can deliver vital supplies before their window of opportunity slams shut.

Snow threatens to bury Ken's pay dirt; Karl ignores his father's advice; Big Al deals with failing equipment and unhappy workers as his first season comes to an end.

Picking their way through Ontario, the guys may have hit the jackpot on a sprawling property full of outbuildings.

A senior has some unfriendly gear in his RV; a Canadian returning from Panama tells all.

An American is busted trying to catch a different kind of trip; officers help a tipsy traveler.

A heavy automobile container hints at trouble; A student's stash of food brings him discomfort.

A traveler returns with a surprise; Marine officers come upon an infested container.

Cesar works with a confused Goldendoodle and a fearful pet parent.

Cesar's rehab of two violent dogs threatening to kill each other continues.

Cesar finds a perfect dog for a single mom and helps a biting mini pinscher.

Cesar rehabs an overprotective Great Dane mix.

A Chihuahua poses a threat to a pet mom's romantic life.

Cesar finds a dog to help a woman heal; he helps a territorial Maltipom.

Cesar rehabs two aggressive German Shepherds, and one very loud Min Pin Mix.

For the first time in the park's history, Hartmann's mountain zebras arrive on the savanna at Disney's Animal Kingdom; babirusa pig Betty is introduced to babirusa pig Mentari, with the hope they will give the park its first-ever babirusa piglet.

Bertie Gregory searches for deadly wave-washing killer whales in Antarctica.

Cesar helps a rottweiler on house arrest and a Pom Terrier to socialize.

For the first time in the park's history, Hartmann's mountain zebras arrive on the savanna at Disney's Animal Kingdom; babirusa pig Betty is introduced to babirusa pig Mentari, with the hope they will give the park its first-ever babirusa piglet.

Bertie Gregory searches for deadly wave-washing killer whales in Antarctica.

Cesar helps a rottweiler on house arrest and a Pom Terrier to socialize.

Cesar works with a confused Goldendoodle and a fearful pet parent.

Cesar's rehab of two violent dogs threatening to kill each other continues.

Cesar finds a perfect dog for a single mom and helps a biting mini pinscher.

Cesar rehabs an overprotective Great Dane mix.

A student is failing his customs exam; officers prevent an artifact from going down in history.

The canine unit brings home the bacon; A traveler discovers she's got a friend in high places.

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.

Art Burke crashes his truck into a snowbank; Alex Debogorski makes his return and faces off with an untested crossing; Mark Kohaykewych tests out new driver Steph Custance; Lisa Kelly faces a monster incline; Darrell Ward runs into rival Todd Dewey.

Karl hopes to score 100 ounces of gold in one week; Ken must deal with an eager employee who keeps breaking equipment.

The guys are ready to drop big bucks on some treasures in British Columbia.

A student is failing his customs exam; officers prevent an artifact from going down in history.

The canine unit brings home the bacon; A traveler discovers she's got a friend in high places.

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.

Albert Lin explores Peru in search of the Lost City of the Cloud Warriors.

In remote Scotland, Albert Lin uses technology to hunt for the powerbase of the Picts, a tribe of barbarians who fought off the Roman Empire.

The Bible describes Nineveh as a wicked city of sin; finding if new discoveries in Iraq and Israel can shed light on the events behind this fearsome reputation.

New discoveries unlock the origins of the Bible's flood story.

Archaeologists discover evidence that sheds fresh light on historical influences from Egypt for the biblical tale of the Exodus.

Archaeologists discover new evidence in Iraq that sheds light on the historical influences of the Bible's Tower of Babel story.

Archaeologists make groundbreaking discoveries about the world of Solomon.

Many persons revile King Herod as one of the evil characters in the Bible; later historians coin him Herod "the Great.".

Is a bog body a murder?; can physics find illness?; who is on an Egyptian bust?

Jeff meets master monster-maker Phil Tippett before venturing on a monster hunt in Bigfoot country.

Wildlife activists Benhail Antao and Louise Remedios attempt to rescue two enormous Indian rock pythons that fell into a well.

Many persons revile King Herod as one of the evil characters in the Bible; later historians coin him Herod "the Great.".

Is a bog body a murder?; can physics find illness?; who is on an Egyptian bust?

Chris goes to South Korea for the tools to change his relationship to pain.

Albert Lin explores Peru in search of the Lost City of the Cloud Warriors.

In remote Scotland, Albert Lin uses technology to hunt for the powerbase of the Picts, a tribe of barbarians who fought off the Roman Empire.

The Bible describes Nineveh as a wicked city of sin; finding if new discoveries in Iraq and Israel can shed light on the events behind this fearsome reputation.

New discoveries unlock the origins of the Bible's flood story.

Lisa Kelly finds herself stranded hundreds of miles from the nearest town; Darrell Ward takes an off-road shortcut; Art Burke encounters a melting ice crossing and a full load; Steph Custance finds out whether she'll become part of the Polar team.

Darrell and Lisa head into Alberta and onto a trail nicknamed The Death Road; Art faces off with the ice crossing where he nearly lost his life last season; Todd takes rookie Steph Custance under his wing as she embarks on her first journey.

Lisa Kelly finds herself stranded hundreds of miles from the nearest town; Darrell Ward takes an off-road shortcut; Art Burke encounters a melting ice crossing and a full load; Steph Custance finds out whether she'll become part of the Polar team.

Darrell and Lisa head into Alberta and onto a trail nicknamed The Death Road; Art faces off with the ice crossing where he nearly lost his life last season; Todd takes rookie Steph Custance under his wing as she embarks on her first journey.

The docs help farmers and friends with a variety of goat problems.

The docs help dogs, a baby beaver, a goose and a parakeet with emergencies.

The docs help dogs large and small with various ailments.

The docs help unusual critters in the clinic and in the field.

The docs lean on their vet techs to save a beloved sick chicken, help a giant schnauzer, and acclimate some wild bass to a new home.

The docs see a goat with severe bloating, a boa constrictor that refuses to feed, and a turtle infected with parasitic "vampire worms.".

The Docs at Critter Fixer treat a rescued pigeon with a surprising injury.

The Docs at Critter Fixer attempt to remove an egg from a cockatiel.

The docs at Critter Fixer attempt to MacGyver a turtle's broken shell.

The Docs at Critter Fixer provide inspiration to animals and humans alike.

The docs get up close and personal with venomous snakes, help a dog whose face droops, and send a diabetic canine on the road to recovery.

The docs at Critter Fixer remove record-breaking kidney stones from a dog.

The docs at Critter Fixer embark on their new "Vet for a Day" national tour.

The docs get up close and personal with venomous snakes, help a dog whose face droops, and send a diabetic canine on the road to recovery.

The docs at Critter Fixer remove record-breaking kidney stones from a dog.

The docs at Critter Fixer embark on their new "Vet for a Day" national tour.

The docs help unusual critters in the clinic and in the field.

The docs lean on their vet techs to save a beloved sick chicken, help a giant schnauzer, and acclimate some wild bass to a new home.

The docs see a goat with severe bloating, a boa constrictor that refuses to feed, and a turtle infected with parasitic "vampire worms.".

The Docs at Critter Fixer treat a rescued pigeon with a surprising injury.

Rookie Steph Custance tries to complete the first ice road mission of her career; Alex Debogorski runs into a road block as temperatures soar; Art Burke attempts to deliver to a new community; Darrell Ward braves an unregulated winter road.

Darrell Ward faces a trail known as "the obstacle course"; Todd Dewey strives to clear a melting ice bridge; Alex Debogorski hauls an oversized fuel tank; Art Burke stumbles onto an ice crossing in the middle of the night.

Rookie Steph Custance tries to complete the first ice road mission of her career; Alex Debogorski runs into a road block as temperatures soar; Art Burke attempts to deliver to a new community; Darrell Ward braves an unregulated winter road.

Darrell Ward faces a trail known as "the obstacle course"; Todd Dewey strives to clear a melting ice bridge; Alex Debogorski hauls an oversized fuel tank; Art Burke stumbles onto an ice crossing in the middle of the night.

The guys look through a hangar-sized collection; Henry's retro service station.

Finland's impressive defence in the Second World War and the nuclear age.

How Britain defended itself from invasion for nearly a thousand years.

The story of Poland's survival, against all the odds.

The story of the Netherlands' most powerful defence - water.

Whistleblower testimony reignites a decades-long fight for transparency.

Commercial pilots come forward about their encounters with UFOs.

Scientists unveil cutting-edge technology helping in the search for UFOs.

People talk about close encounters they've had with UFO phenomena.

Reports from people who say they've been abducted are explored; a Harvard psychiatrist who takes them seriously comes under attack.

No longer waiting for the government to share data, citizen scientists and private groups amplify the search for answers.

Chris turns to longevity doctor Peter Attia to find out how changing his eating habits can help his quest for longevity. Ironically, the answer is to eat no food at all for four days, which will unlock his body's own anti-aging powers.

Can Chris stop playing it safe and rediscover the joy of taking risks?

No longer waiting for the government to share data, citizen scientists and private groups amplify the search for answers.

Chris turns to longevity doctor Peter Attia to find out how changing his eating habits can help his quest for longevity. Ironically, the answer is to eat no food at all for four days, which will unlock his body's own anti-aging powers.

Can Chris stop playing it safe and rediscover the joy of taking risks?

The story of Poland's survival, against all the odds.

The story of the Netherlands' most powerful defence - water.

Whistleblower testimony reignites a decades-long fight for transparency.

Commercial pilots come forward about their encounters with UFOs.

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.

A woman returning from a trip to China has business cards to a Sydney brothel and passports for three Chinese girls.

An old map connected to testimony from an 1891 eyewitness account of Slumach's hanging sheds light on the legend.

Conservation Officer Logan has a close call while investigating a case of poaching; an aggressive grizzly bear ransacks a remote trapper's cabin.

Glass brought light into homes and put the world into focus; people use glass to protect ourselves, cure disease, and create artistic masterpieces.

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.

A woman returning from a trip to China has business cards to a Sydney brothel and passports for three Chinese girls.

An HSI stakeout leads to nearly $500,000 of meth and fentanyl in San Diego; CBP finds concealed cash and a carload of cocaine at the El Paso border.

PR AMO team hunts down boat loaded with $41 million of coke; CBP gets a tip about money smugglers and finds cocaine and people inside car trunks.

HSI performs an undercover drug sting; CBP finds cocaine in Rio Grande Valley.

CBP's K9 sniffs out hidden cash; HSI intercepts a $2 million drug deal.

CBP in JFK and HSI in San Diego tackle fentanyl crisis on opposite coasts.

HSI partners with Colombian National Police to dismantle illegal gold mining operations; CBP thwarts cartel activity in Texas.

HSI money laundering stings; CBP's largest drug seizure in LAX history.

The residents of Port Protection build a life-changing tool.

PR AMO team hunts down boat loaded with $41 million of coke; CBP gets a tip about money smugglers and finds cocaine and people inside car trunks.

The search for crab takes residents into a dangerous new environment.

The residents of Port Protection build a life-changing tool.

In this enhanced episode, AMO Puerto Rico finds cocaine on a ferry.

The search for crab takes residents into a dangerous new environment.

An HSI stakeout leads to nearly $500,000 of meth and fentanyl in San Diego; CBP finds concealed cash and a carload of cocaine at the El Paso border.

PR AMO team hunts down boat loaded with $41 million of coke; CBP gets a tip about money smugglers and finds cocaine and people inside car trunks.

HSI performs an undercover drug sting; CBP finds cocaine in Rio Grande Valley.

CBP's K9 sniffs out hidden cash; HSI intercepts a $2 million drug deal.

A piece of salmon comes up positive for cocaine; Syrian carpets have something suspicious woven into the fabric.

A man arrives from Beijing with strong readings for narcotics; three men want to visit a temple that hasn't been built yet.

A woman's belongings are positive for heroin; a Malaysian man arrives looking for work.

A woman with protruding pants attracts the attention of Customs; a passenger would rather go to court than pay a fine.

A recurring mine marker points the team east to neighboring Harrison Lake as leads and legend line up; clues found in a 1950s article by an investigative reporter place a lost Spanish gold mine directly on Slumach's path.

When a bear charges a group of remote researchers, a Conservation Officer deals with the potentially life-threatening situation, and Ray takes on a challenging recovery that bested two tow companies before him.

The fundamental creation of the wheel helps shape the human experience, but if the wheel suddenly stopped working and society lost the greatest, game-changing accomplishments made using wheel technology, the world would be vastly different.

A piece of salmon comes up positive for cocaine; Syrian carpets have something suspicious woven into the fabric.

A man arrives from Beijing with strong readings for narcotics; three men want to visit a temple that hasn't been built yet.

A woman's belongings are positive for heroin; a Malaysian man arrives looking for work.

A woman with protruding pants attracts the attention of Customs; a passenger would rather go to court than pay a fine.

In this enhanced episode, the causes of three disasters are dissected.

Three real-world disasters forensically dissected - Deepwater Horizon explosion, the Concorde crash and the funicular fire at Kaprun.

The causes of three disasters involving a high-rise, a submarine and a subway station are dissected.

In this enhanced episode, the causes of three disasters are dissected, a nuclear plant, a tunnel and a department store.

Enhanced; three real-world disasters dissected: in space, a train and a high-rise.

Enhanced; three real-world disasters dissected: nuclear missile, ferry and oil rig.

In this enhanced episode, the causes of three disasters are dissected; Lac-Mégantic train crash, Imperial Sugar refinery explosion and Ever Given container ship accident.

Three real-world disasters forensically dissected: Fukushima nuclear plant, a Manhattan crane collapse, fire on the aircraft carrier USS Forrestal.

Will travels to a remote South Pacific island threatened by rising seas.

Will travels to the Kalahari Desert to learn the secrets of the San people.

Psychologist Modupe Akinola challenges Chris to stay calm during a terrifying walk along a crane that's projecting from a skyscraper. Chris learns powerful techniques to control stress in his life and combat the risk it poses to long-term health.

Will travels to a remote South Pacific island threatened by rising seas.

Will travels to the Kalahari Desert to learn the secrets of the San people.

In this enhanced episode, the causes of three disasters are dissected.

Three real-world disasters forensically dissected - Deepwater Horizon explosion, the Concorde crash and the funicular fire at Kaprun.

The causes of three disasters involving a high-rise, a submarine and a subway station are dissected.

In this enhanced episode, the causes of three disasters are dissected, a nuclear plant, a tunnel and a department store.

A woman tries to smuggle an expensive gift into Australia; a package from Hong Kong looks suspicious.

A fidgety passenger has officers on high alert because of what's found under his home's floorboards.

A musician claims to have special powers that help her see the future.

A father and son from China have four suitcases full of undeclared food; an immigration raid targets illegal workers.

The source of Slumach's lost gold.

Frigid temperatures wreak havoc on Dawson City, putting the fire department in danger; an avalanche shuts down the Klondike Highway and a tow operator races to find a driver who has plunged off-road and into an icy river.

Exploring what the world would be like if salt and all of its vital contributions, from food preservation to enabling industry, were to suddenly disappear.

A woman tries to smuggle an expensive gift into Australia; a package from Hong Kong looks suspicious.

A fidgety passenger has officers on high alert because of what's found under his home's floorboards.

A musician claims to have special powers that help her see the future.

A father and son from China have four suitcases full of undeclared food; an immigration raid targets illegal workers.

Alaskans confront brutal elements while on the hunt for critical resources.

Alaskans engineer inventive solutions for survival in the harsh elements.

With surprises around every bend, Alaskans must be ready for anything.

Alaskans brave the deadly cold of winter to protect their way of life.

The next generation must be resourceful tackling late winter challenges.

The next generation of Alaskans risk it all to ensure their survival.

Alaskans must push their boundaries in hopes of a prosperous future.

As the seasons change, the next generation must adapt in order to survive.

Vintage rackets, a live dog and a soldier's uniform are returned to owners.

Defensive dogfighting proves a tough test, as instructors go for the kill.

As the seasons change, the next generation must adapt in order to survive.

Vintage rackets, a live dog and a soldier's uniform are returned to owners.

Defensive dogfighting proves a tough test, as instructors go for the kill.

Alaskans confront brutal elements while on the hunt for critical resources.

Alaskans engineer inventive solutions for survival in the harsh elements.

With surprises around every bend, Alaskans must be ready for anything.

Alaskans brave the deadly cold of winter to protect their way of life.

An American tourist is caught renting by the hour, but insists she needs to meet up with her boyfriend.

At O'Hare International, a returning American's bananas cause a slip-up in secondary; a mother covers for her kid at Detroit's Ambassador Bridge; a car search is brought to a head in Washington State.

Officers search for a fugitive in Washington State; a cook is questioned on his way to Las Vegas; a canine flags several packages in Chicago; x-rays discover anomalies in Port Huron cargo.

An officer's expertise in body language pays off; a German rock band in Detroit; a hole in a traveler's story.

It's up to Adam to push forward and guide the team through the uncharted terrain of Corbold Canyon.

Multiple 911 calls push Dawson City to the brink as they battle to save a family home and a historic building, while snowstorms pummel Whitehorse, causing chaos and forcing a dangerous backcountry helicopter rescue mission.

The world is literally buzzing with insects; bees, spiders and insects of all shapes and sizes touch every aspect of life, they're the essential workers that pollinate food, clean up the dead and are an integral part of the ecosystem.

An American tourist is caught renting by the hour, but insists she needs to meet up with her boyfriend.

At O'Hare International, a returning American's bananas cause a slip-up in secondary; a mother covers for her kid at Detroit's Ambassador Bridge; a car search is brought to a head in Washington State.

Officers search for a fugitive in Washington State; a cook is questioned on his way to Las Vegas; a canine flags several packages in Chicago; x-rays discover anomalies in Port Huron cargo.

An officer's expertise in body language pays off; a German rock band in Detroit; a hole in a traveler's story.

Dr. Pol and his team handle animal emergencies in Central Michigan.

A cow requires the doctor's assistance.

Dr. Pol needs to take blood samples from a flock of sheep to test for Ovine Progressive Pneumonia, a progressive, incurable and highly contagious disease.

Dr. Pol examines a goat that has been refusing to eat.

Dr. Pol and Diane celebrate a milestone that's been decades in the making.

Dr. Pol celebrates turning 80 with a trip to the Netherlands with Diane.

The Pols welcome a fluffy addition to the family; Tater is not pleased.

Beth, Erin and Kerri introduce Linus, a male mandrill, to a family of female mandrills; Nicole has a soft spot for a stinky pair of hyenas with spotty reputations; Susan helps Sohni, an eight-year-old Sumatran tiger, face a challenge.

Bertie tracks and films African wild dogs, one of the world's top predators.

Welcome to the fair; Vets rally to keep dreams alive for hardworking kids.

Scientists race to save the last two northern white rhinos from extinction.

Bertie tracks and films African wild dogs, one of the world's top predators.

Welcome to the fair; Vets rally to keep dreams alive for hardworking kids.

Dr. Pol and his team handle animal emergencies in Central Michigan.

A cow requires the doctor's assistance.

Dr. Pol needs to take blood samples from a flock of sheep to test for Ovine Progressive Pneumonia, a progressive, incurable and highly contagious disease.

Dr. Pol examines a goat that has been refusing to eat.

A Chicago canine unit discovers smugglers; officers enter a high-speed chase in Port Huron; a traveler triggers radiation alarms; bullets in Blaine, Washington.

In Detroit airport, a family travelling from the UK, may need to corroborate their story. Also a tip from authorities, puts officers at the Chicago International Mail facility on high alert.

Border officers stop a young British visitor meeting an American cyber pal at Detroit Metro Airport, and a Chinese traveller is caught using his mobile phone in a secondary inspection in Chicago.

A strong odor leads to a secondary inspection for two Americans in Port Huron; an officer finds gold at Chicago's O'Hare Airport.

According to a 1980s author and historian, the Spanish have a long and hidden history of gold exploration in Pitt Lake, and Slumach found their cache.

As winter tightens its icy grip, the small, isolated community of West Dawson finds itself completely cut off from emergency services. Alone, Ray faces a string of dangerous solo vehicle retrieval missions on a storm-battered highway.

Examining the history of cats and dogs and how they have been helpful companions to humankind all over the globe.

A Chicago canine unit discovers smugglers; officers enter a high-speed chase in Port Huron; a traveler triggers radiation alarms; bullets in Blaine, Washington.

In Detroit airport, a family travelling from the UK, may need to corroborate their story. Also a tip from authorities, puts officers at the Chicago International Mail facility on high alert.

Border officers stop a young British visitor meeting an American cyber pal at Detroit Metro Airport, and a Chinese traveller is caught using his mobile phone in a secondary inspection in Chicago.

A strong odor leads to a secondary inspection for two Americans in Port Huron; an officer finds gold at Chicago's O'Hare Airport.

Archaeologists exploring the origins of the civilisation that built the great city of Angkor investigate ancient lost treasure discovered in Laos.

The discovery of gold and silver artifacts in Laos, dating to the early days of the Khmer Empire, leads scientists to investigate how the objects were made; on their journey, they retrace the steps of the ancient kings.

A look into how the T-Rex became king of the dinosaurs.

A look into how prehistoric land mammals evolved into top ocean predators.

How the giant ice age mammoth became extinct.

Taking a look at the excavations in the La Brea Tar Pits in Los Angeles and showcasing how the pits can help unravel the mystery of how the saber-toothed tiger hunted its prey.