Original subtitles

[tense music]

- [Danny] Mysteries can be buried anywhere.

Under the earth,

[volcano rumbling] [plane whooshing]

beneath the sea,

or even right under our own feet.

[coins jingling]

And when we stumble upon them,

sometimes what we find can change history.

Tonight, some of the deadliest discoveries ever uncovered.

From an unsettling ancient tower...

- What they see is just chilling.

It's a wall made up entirely of human skulls.

- [Danny] To a destructive blast from the past...

- Fires raged across the globe

and acid rain showered down from months on end.

It was truly biblical,

end of times kind of stuff.

[thunderous explosion]

- [Danny] To a place so toxic, even the air will kill you.

- The pathogens that have been released here

could bring back some of the world's

deadliest biological weapons.

- Join us now, because nothing stays hidden forever.

[mysterious music]

When you think of Yellowstone,

you might picture roaming bison, beautiful nature,

or peace and quiet.

But beneath the ground, something deadly is stirring,

and it could strike any day.

[rocket whooshing] [tense music]

- In 1965, NASA begins a mission

to map the surface of the Earth from space.

They plan to use state-of-the-art cameras

mounted on satellites,

but to make sure the images they are getting are accurate,

NASA decides to make

a control set of pictures on the ground, at Yellowstone.

- They're making this map of Yellowstone

so that they have a baseline,

and the person in charge, his name is Bob Christiansen.

- Yellowstone has the ideal geology to do this,

because the park is just chockfull of geysers

and these natural pools,

all of which can test the real accuracy of these cameras.

- Because Christiansen is also a geologist,

the National Park Service also has him collect rock samples

that are later carbon-dated.

- [Danny] These rock samples reveal something strange.

- It turns out that most of the rock in Yellowstone

is made up of something called rhyolite,

which only occurs when you have lava flowing

or volcanic explosions.

But there are no active volcanoes in Yellowstone.

- Still, Christiansen's data doesn't lie,

the bulk of the park's geology

is the result of several massive eruptions

over the last two million years.

- [Andrew] There are hundreds of unique geological features

across the park.

So Christiansen's first thought

is that these were the product of an ancient volcano chain

that has long since gone dormant.

- [Danny] But when NASA's satellite mapping of the park

is finally finished in 1972,

Christiansen is shocked

by what the infrared pictures reveal.

- What the images tell him

is that the unique geological features of Yellowstone

were not, as he thought,

formed by an ancient chain of volcanoes,

but by a single supervolcano.

[eruption booming]

- [Don] Of the over 1,000 volcanoes we know of on Earth,

only about 20 are supervolcanoes,

and this is one of the biggest ever found.

- The biggest of these eruptions took place

two million years ago.

This eruption launched as much as 600 cubic miles

of red, hot lava and rocks into the air.

This is an explosion 2,500 times bigger

than the Mount St. Helens eruption.

- [Danny] Surprisingly, Yellowstone's fury

may not be finished.

- [Andrew] Even though it has been dormant

for a half a million years,

lava still flows in this massive super volcano

underneath Yellowstone National Park.

- [Danny] But in 2022, what scientists uncover

is far more alarming than anyone imagined.

- [Don] A study published in the journal Science

shows that lava chambers under the park

are rapidly filling.

- [Andrew] This, combined with the fact that

Yellowstone has over 3,000 earthquakes a year

leads some to speculate

that the supervolcano may be preparing to erupt,

once again.

- [Sami] If the next eruption is anything like the last one,

it would spew enough debris into the sky

to block out the sun

in the western United States for decades,

leading to widespread famine and economic collapse.

- [Don] Considering the Yellowstone supervolcano

has remained dormant for over a half million years,

let us hope for another half million, at least.

- Not all threats erupt.

Some, like one frozen killer in Siberia, melt.

[tense music]

- In a small town in northwest Siberia,

a farmer is surprised to find the carcass

of one of his reindeer.

[herd rumbling]

Now, it's not unusual, every now and then,

an animal will die of some kind of natural causes.

But over the next month, other local farmers watch as

more and more reindeer livestock get sick and die.

[eerie music]

- [Sami] In all, over 1,200 reindeer end up dying.

At first, the villagers chalk it up to

the stress the animals are undergoing

due to that summer's unusually high temperatures,

but then suddenly, the villagers start getting sick.

- [Danny] Locals develop high fevers and painful sores.

- [Don] 90 villagers fall critically ill

and are hospitalized.

Tragically, one sick child dies.

- Doctors are completely baffled.

They're running blood tests and throat swabs,

but every test that they run ends up coming back negative.

- [Danny] Then finally, one test comes back positive

and the result is shocking.

- It's Bacillus anthracis,

but we know it more commonly as anthrax.

[dramatic music]

- Most people think of anthrax as a biological weapon,

but it actually occurs naturally

in soils throughout the world.

When animals like reindeer graze,

they kick up the spores and form little dust clouds

and then the animals can inhale this and become infected.

- [Don] Once it's in the body, the bacteria grows quickly.

It causes fevers and difficulty breathing.

And after an infected animal dies,

its body decomposes, spilling even more anthrax spores

right back into the earth.

- The spores can sit there for decades

like this ticking time bomb

just waiting for its next unfortunate host.

Even with treatment, the fatality rate in humans

can be as high as around 80%.

- [Danny] As government officials

rush to figure out the source,

they discover that in the early 1900s,

Siberia was ravaged by a series

of terrible anthrax outbreaks.

- [Sami] More than a million reindeer died

with their infected carcasses sprawled out

everywhere across this tundra.

- [Don] Some of those remains were frozen in the permafrost,

essentially refrigerating the dead deer

and the bacteria inside of them.

- [Stephanie] But then, starting in the year 2011,

the area has five years

of unusually warm summers.

- [Don] And the extreme heat begins to melt the permafrost,

exposing dormant anthrax spores.

- [Danny] To contain the outbreak,

officials scour the tundra,

burning thousands of infected reindeer carcasses

and vaccinating tens of thousands of living reindeer.

- Gradually, this works,

and the number of new cases begins to slow

and then eventually, completely stop.

- [Don] But it's very likely that more pathogens

lie frozen under the Arctic ice.

- [Sami] If rising temperatures continue to melt the permafrost,

it is very likely that animals and humans

will be exposed to these ancient pathogens

which modern humans have never had exposure to before.

As one researcher puts it, "This is Pandora's box."

- In Mexico City,

a construction crew starts a routine day on the job.

What they uncover should have stayed buried.

[tense music]

- One morning in 1978,

electrical workers are digging in an area of Mexico City

to install an underground power transformer.

But work comes to a stop when they hit

what appears to be a boulder.

- They start digging around this thing

and they realize very quickly that this is no ordinary rock.

- [Danny] It's a 10 foot circular stone

with very detailed carvings.

- It depicts a female figure.

However, scattered around it are body parts

all cut into pieces.

Archeologists are called in

and they immediately identify the figure as an Aztec god.

- [Sami] The image is actually the ancient Aztec female deity

known as Xochiquetzal.

- [Austin] And it's believed a stone once stood

at the entrance to the Aztecs' primary temple,

the Templo Mayor.

However, it's been missing for centuries.

- [Danny] From the early 1300s,

the Aztecs were a powerful empire for 200 years,

centered in modern day Mexico.

This stone gives us more insight into their culture.

- In the Aztec belief,

this deity, shown on the front of this temple,

dismembered and disfigured,

is meant to serve as a warning

for anybody that would try to enter the temple.

Basically, if you mess with us,

this is what's going to happen to you.

- And they're not joking around,

because the Aztecs regularly and persistently

sacrificed people on the pyramid,

which she sits at the base of.

- [Danny] These human sacrifices

were huge spectacles with large crowds.

- According to firsthand accounts in the 1500s,

many of the victims are decapitated.

- [Don] Other times, they were stabbed

and had their hearts removed from their body.

The heart would be held up

in front of the crowd while it was still beating,

and the lifeless body

would be tossed down the temple stairs.

At one point, it's even said,

"The Aztecs sacrificed 4,000 of their enemies

at the same time."

- [Danny] But in 1519, the Spanish arrive

and weakened the Aztecs

with a one two punch of guns and disease.

- The Spanish then proceed to

wipe out the Aztec native religion

and force Catholicism upon the populace.

- [Danny] As the Aztec religion is erased,

most of its important artifacts and relics

are lost or destroyed.

But the discovery of the circular stone

leads researchers to take a closer look

at the surrounding area,

where they make an even more disturbing find in 2015,

- [Austin] A building is being renovated

very close to where they found the stone.

Workers dig under the structure when they find

a chamber made of volcanic rock walls

with a flagstone floor.

- [Sami] And when they look inside the chamber,

what they see is just chilling.

It's a wall made up entirely of human skulls.

[eerie music]

- Over the next two years,

archeologists discover that this wall of skulls

is actually a giant skull tower called a Tzompantli.

- [Danny] For centuries,

stories of a towering wall of skulls

were dismissed as legend,

but this discovery proves it was real

and far bigger than anyone imagined.

- [Austin] Over the next couple years,

the archeologists continue to excavate

and discover around 600 more skulls,

but they do believe that at one point in time,

it held over 60,000.

- [Sami] Historians are working to put answers together, but

it seems likely that there are

many more sacred secrets of the Aztecs

hiding under Mexico City.

- Halfway across the world,

another ancient tomb guards a secret

tied to one of history's most dangerous empires.

[tanks booming]

- [Sami] It's April 1944,

World War II is raging across Europe,

and some of the countries that are allied with

Adolf Hitler and the Nazis

are just getting hammered by the Allies.

- One of those Axis powers is Bulgaria,

which is under attack from two different directions.

It's being bombed by the Americans

and the British from the West,

and the Soviets from the east.

[gunfire booming]

- The Bulgarian army is desperate,

so they start building a series of underground

bomb shelters and trenches

surrounding the central city of Kazanlak.

- [Sami] As they dig,

a few of the soldiers hit something hard.

- [Patrick] The men chisel a hole in the wall

and when they bust through ,

on the other side, they find an underground chamber.

They go through and they find themselves in a tunnel.

- [Don] One of the men flicks on his flashlight.

He's surrounded by richly colored frescoes

depicting men in battle.

The soldiers call the director of a local history museum

who realizes this is an important discovery.

- [Danny] Learning more will have to wait.

As the Soviets bear down, Bulgaria switches sides

and declares war on Germany.

This stops the allied bombing

and very possibly saves the mysterious tunnels.

But after the war, experts return to open the site.

- [Don] The passageways with the frescoes

lead to a round domed chamber with even more murals.

It turns out this accidental find is an ancient tomb.

- [Patrick] But not just any tomb;

they find fragments of a crown.

This is a royal tomb.

- [Sami] Further exploration research of this one tomb

actually suggests that it's a small part

of a much larger underground royal cemetery.

- [Danny] Experts soon realize

this incredible find includes tombs

belonging to the rulers of Thrace,

a famous kingdom known for its fierce warriors.

- [Sami] Thrace is a big deal to those who study ancient history.

Thrace covered modern day Bulgaria, Turkey,

Romania, and Serbia,

from the fifth century to the third century BC.

- [Don] Eventuall, Thrace is conquered by Rome,

but some of Rome's most famous warriors ,

like Spartacus, were Tracian, as were a few Roman emperors.

So the discovery of a vast Thracian tomb

is really exciting.

But the real treasures of the tombs are the frescoes

which adorn the walls and ceilings.

- [Sami] They include a couple, seated at a banquet table

preparing to enter the underworld.

You've got another one depicting a chariot race,

which is part of the funeral games

when a member of the elite died.

- We don't have much from the Thracians themselves.

We know a bit about their language,

but we don't have any extended texts in it.

So when you find direct evidence of

what the rich and powerful in Thrace were doing

and what they valued,

that's incredibly rare and incredibly valuable.

- On a Soviet research ship, a routine mission,

collecting plant and fish samples

takes a fatal turn when one crew member

brings home a very different specimen.

- It's mid-July in the Aral Sea,

and the 12 person crew

of the Soviet research vessel, Lev Berg,

is collecting water samples and other sea creatures

in an effort to identify

why there is a dramatically declining population of fish.

- The youngest member of the crew is a 24-year-old female

who is working on the deck collecting fish and plants

and then takes them below deck to evaluate them

and then incorporate them into her lab journal.

- One morning, the ship approaches

a remote island called Vozrozhdeniya,

otherwise known as Rebirth or Resurrection island.

- This island was once home

to a very picturesque fishing village,

but today, as the ship passes by,

it moves through a mysterious brown haze.

- [Danny] The passengers don't think much of it

and continue on with their research project.

- [Martin] On August 6th, they returned to Aralsk,

and the female researcher had developed an illness

during the last five days of the cruise,

and as soon as they put into port, she rushes home.

- She's suffering from fever, coughs, muscle aches.

The doctor prescribes antibiotics and aspirin,

but then, a very angry looking rash

begins to occur on her face, back,

and other areas of her body.

- [Kavitha] Eventually, her fever breaks and she recovers,

but then her nine-year-old brother

comes down with a fever as well

and also develops a skin rash.

The boy's entire body is covered with painful lesions.

- [Geoffrey] The boy's school teacher comes to visit with him

and then she too gets very ill.

She can't eat or drink, she gets high fever,

and gets covered with sores everywhere, on her body,

face and scalp,

so many sores that there's like no space between them.

She dies soon after.

- [Danny] The boy's parents are terrified

and call a pediatrician to the house to examine their son.

When he does, he's shocked.

- After multiple incorrect or simply wishful diagnoses,

the correct diagnosis is finally made: smallpox.

- [Martin] This is really strange

because both the researcher and her brother

had been vaccinated against smallpox.

She doesn't have any idea

how she could have contracted the disease.

- [Danny] Over the next few weeks,

eight more people come down with smallpox,

and sadly, three die.

- [Rick] The Soviet government shuts down

the entire town of Aralsk,

stopping all transportation in or out,

and the 50,000 people are vaccinated against smallpox

in two weeks.

- Quick containment of the virus

helps to prevent a full-blown outbreak of smallpox,

and the authorities never take any responsibility.

- [Danny] It's not until 30 years later

that the source of the outbreak is finally uncovered.

- [Rick] Turns out that for many years, the Soviets

had been using Vozrozhdeniya Island as a test site

for some of the world's most deadly pathogens.

- [Martin] The site is called Aralsk-7,

and on it, they were developing anthrax, smallpox,

antibiotic-resistant bacteria,

and other diseases that the world had never seen.

- [Rick] When the Lev Berg passed

close to the island in 1971,

the female researcher was the person to get it

because she had spent more time on deck than anyone else.

- And even though she was vaccinated, she got it,

because the Soviets were weaponizing smallpox virus

so that it would evade people

who were vaccinated and infect them.

- [Martin] When Aralsk-7 is ultimately

abandoned in the 1990s,

the Soviets pump formaldehyde across the entire island

in an attempt to kill everything there

because the pathogens that have been

released here can survive for centuries,

and it could bring back

some of the world's deadliest biological weapons.

- Imagine stumbling across an even older, deadlier find.

That's exactly what happened to one man in 2022.

[tense music]

- [Don] In April 2022, a fabric designer named Philip Jacobs

is out for this leisurely stroll

along the beach near Cambridge Bay in southern England.

- It's part of his regular routine,

a chance to get some exercise

as well as partake in one of his favorite pastimes:

scouring the beach for hidden treasures.

- [Danny] Over the years, many fossils have been discovered

on this stretch of beach,

leading to its nickname, the Jurassic Coast.

- As Jacobs walks along the shoreline,

he catches a glimpse of an object

that looks like just a piece of driftwood.

- [Don] So he takes a closer lookm

and what he finds is this two-foot long snout,

complete with these massive teeth,

and Jacobs knows he has found something cool,

but he isn't exactly sure what it is.

- In the meantime, he contacts a friend

who's a paleontologist named Steve Etches,

and he brings him to the site.

- [Danny] Etches takes one look at the snout

and can hardly contain his excitement.

- Jacobs' found part of the skull of a pliosaur,

a marine reptile that lived with the dinosaurs,

also known as the Sea-rex,

which is a nod to its fearsome land equivalent, the T. rex.

- Pliosaurs ruled the water 150 million years ago.

They were massive creatures.

They could grow to about 40-feet long,

which is about the size of a school bus,

and they were the apex predators of the sea.

- And they didn't take a backseat to anyone

due to their extremely powerful jaws.

Today, saltwater crocodiles

are known to have the strongest bite of any living creature,

but the pliosaur was at least twice as powerful.

- [Danny] Etches and his team continue searching the area,

hoping to uncover even more of the Sea-rex.

- [Don] As they climb way up the mountainside,

eventually excavating the rest of the skull,

which turns out to be over six-feet long,

completely intact with no missing bones.

Jacobs' discovery reveals anatomical features

that researchers haven't seen before,

including one that is believed to be

a light sensitive third eye, used for stalking prey.

- And his friend Steve Etches

thinks that this is just the beginning.

- [Don] He thinks the rest of this creature

is somewhere buried here, and is going to reveal even more,

and it's all due to one guy who went for a stroll

on a local beach.

- It began like any hunt for treasure,

digging for riches buried in the ground.

What followed was truly chilling.

[tense music]

- In 1993, on the Altai mountains

near the Russia-China border,

you have grave robbers

who have been looting burial mounds in the region.

- This has been going on for years.

The local Altain tribe, they consider these mounds sacred,

so they've had enough.

- They decide that they want to take action,

so the call on the Russian border patrol.

[guns cocking] [dog barking]

- [Kavitha] By the time Russian border patrol arrives,

the thieves are long gone,

but they wanna make sure that the site

is handled respectfully.

So they call in Dr. Natalia Polosmak

who is a renowned archeologist

that specializes in these ancient cultures.

- [Saim] There's one large burial mound

that has clearly been vandalized,

so Polosmak and her team investigate

and they find that one shallow grave has been robbed.

- But what was interesting

is that she found a shaft below that grave,

and it was obvious to her

that the shaft wasn't something from recent times.

- [Kavitha] So she suspects that this grave

might have been robbed years ago,

but she also suspects that it might sit

on top of something else.

So the team keeps digging

and eventually hits a huge block of ice.

They've uncovered a layer of permafrost underneath the dirt.

- [Danny] The team carefully melts the ice

with boiling water,

hoping to preserve whatever they find beneath.

- [Sami] As they continue working their way through,

they find something astounding,

the frozen remains of six ancient horses.

- In elite burials, they would sacrifice the horses

that belonged to the person who died

and bury them around the grave.

And so, finding these horse carcasses

means they've stumbled on a really prestigious burial.

- [Danny] Alongside the horses,

the team uncovers a large wooden chamber

with an ornate coffin inside.

But who is the very important person buried here?

- When they open the coffin,

Dr. Polosmak her team are stunted by what they find.

A perfectly preserved, mummified woman.

- One of the team members calls her the

Siberian Ice Princess, and the name sticks.

- Researchers estimate that the Ice Princess

lived about 2,600 years ago.

- She has this elaborate headdress

with carved wooden animals on it covered in gold leaf.

- On the surface of her skin,

they discover very detailed tattoos.

- [Sami] And even more incredibly,

the ink still looks fresh,

like she almost had this work done yesterday.

- [Danny] The tattoos, horses, and grand burial

suggest the princess may have served a religious purpose

as a tribal priestess.

- Against the wishes of the Altain tribe,

Polosmak and her team decide to move the body to university

for further study.

They perform an MRI on the body

and they conclude that the princess died young,

anywhere between the ages of 25 and 28,

and they find that the cause of death was breast cancer.

- [Danny] Although the Altains aren't happy,

the Ice Princess gets moved again, this time to a museum.

- [Sami] The Altain tribe believed that

removing mummies from their resting place

is a terrible omen.

They even blame the removal of the mummy

for causing a series of local floods and earthquakes.

- [Danny] Eventually, Russian authorities

send the ice princess back to her homeland.

- [Sami] They restrict any more digging

and they declare the area to be a zone of peace

so that the dead may finally rest.

- Over 7,000 miles from Siberia

lies another mysterious grave,

but this one wasn't carved by humans.

It was blasted into the Earth from space.

[tense music]

- In 1978, a young geophysicist named Glen Penfield

moves to Mexico to work for an oil company,

and he spends his time flying back and forth

across the nation,

using magnetic to pinpoint the place

to build new oil wells.

- Within a few months,

he has flown over half the eastern coastline

with nothing to show for it.

All he finds are flat magnetic readings.

It all looks kind of the same, no black gold.

- But one day, Penfield sees these two magnetic lines

on his screen.

Both of them have a shallow dip in them,

which tells him that there's something strange

in the water down there.

So he follows these lines

and he discovers that these anomalies

seem to get stronger the farther he goes.

- [Don] The strange readings fall

in a concentric circle pattern

that creates a bulls-eye about 110 miles wide,

half on land and half over water.

- Then it just hits him.

As a kid, he had been fascinated with the moon

and its impact craters.

And so he wonders, could this be a giant impact crater

from a meteor strike?

- [Austin] Penfield presents his crater impact theory

to his bosses and then fellow colleagues

at a geophysics conference,

and they all laugh it off as Glen's sky rock.

- Then in 1990, 12 years after his initial discovery,

he gets a call out of the blue

from a grad student named Alan Hildebrand.

Hildebrand is writing a paper about the sudden extinction

of the dinosaurs millions of years ago,

and he thinks there could be a connection

to Glen's asteroid impact theory.

- [Danny] Hildebrand tracks down a rare core sample

from the possible impact site in the Gulf of Mexico.

- [Don] And lo and behold, when they analyze the sample,

they discover an unusual form of rock called shocked quartz.

- [Danny] Shocked quartz is formed by intense pressure

due to large scale impact events.

- That means this rock could only have been formed

by a massive asteroid.

- [Danny] Finally, Penfield is vindicated.

- [Austin] Penfield, Hildebrand and several other scientists

publish their findings in the journal Geology.

- [Danny] They call it the Chicxulub crater

after the seashore town

where the magnetic anomalies were first discovered.

- [Don] Subsequent testing finds that the Chicxulub asteroid

struck Earth 66 million years ago,

the same time the dinosaurs disappeared

from the fossil record.

- Scientists continue researching

and find that what happened after this giant space rock hit

is pretty terrifying.

- [Don] Fires raged across the globe,

a half mile tsunami crashed into the Americas,

an acid rain showered down for months on end.

It was truly biblical.

End of times kind of stuff.

- It didn't just kill all the dinosaurs,

but also 75% of all plant and animal life on Earth.

- Instead of an oil well,

Glen discovered something else truly astonishing,

proof that it was his sky rock

that nearly wiped out all life on Earth.

- Picture this: it's a spring Saturday in 1950.

You and your brother are wading through a bog

just outside your tiny village in Denmark.

It's an eerie place on the best of days,

but today, it's about to get even stranger.

[tense music]

- Two brothers, Viggo and Emil Hojgaard,

are harvesting this wet, spongy carpet of peat.

Peat can be cut into brick form

and burned for use in cooking and heating their houses.

- Now as the brothers are digging deeper

into the vegetation,

they hit something that feels off.

- They start digging deeper and deeper into this hole,

until they see a face looking right back up at them.

- It is definitely a body, and it looks like a recent burial,

because the skin and the soft tissue is intact,

it hasn't decomposed.

- The body is male, he's wearing a pointed sheepskin cap,

and a belt around his waist,

but other than that, he's totally naked.

- [Don] The corpse is on the small side,

a bit like a child curled up in a fetal position.

And a terrible thought occurs to these brothers,

A schoolboy nearby has recently gone missing;

this must be his dead body.

- So the brothers make the trek

to the nearby village of Silkeborg

to notify authorities of their dark finding.

- [Kavitha] Police investigate,

but some things just don't add up.

There are no signs of digging, so how did it get so deep?

- [Don] Even weirder is that the corpse's nails

are cured and blackened,

and the skin is this bluish-black color.

- [Danny] Police call in archeologist Dr. P.V. Glob

from a local university to help.

- Dr. Glob takes a look at the body

and he knows one thing conclusively:

this is not a recent death.

He doesn't know how old it is, but it's old.

- [Danny] Then, the professor

shares something even more disturbing.

- [Kavitha] When he removes a lump of peat

next to the corpse's head,

he finds two leather ties twisted into a rope

around the corpse's neck.

It's clear that this person did not die of natural causes.

- In order to study the body properly,

Glob realizes that they have to move the body from this bog

to the National Museum of Denmark in Copenhagen.

- [Danny] When they finally make it to the museum,

Dr. Glob makes another surprising discovery.

- [Don] Even though it's perfectly preserved,

the body turns out to be over 2,300 years old.

It is from the Iron Age, and it isn't a child.

From dental analysis, they estimate that he is between

30 and 40 years old.

They nickname him the Tollund man.

- [Danny] But why is he so well preserved?

- [Sami] The moss, which covers the entire surface of the bog,

it's called sphagnum, and it discolors

and preserves the skin and the hair.

- [Kavitha] The moss makes the bog water highly acidic.

This turns the skin

and soft tissue into a leather-like material that,

under the right conditions, can last for centuries.

- Peat bogs also lack oxygen, which means that

the microorganisms that cause decay

in dead bodies can't survive.

Coupled with that acidic water,

you have the perfect recipe for preservation.

- [Danny] This also allows experts

to figure out how he died.

- [Kavitha] Analysis of his neck

and the rope that he was buried with

pinpoint that the cause of death was hanging.

- [Danny] Back in the Iron Age,

people were hanged and killed not only for crimes,

but as ritual sacrifices.

- To the ancient people

who placed the Tollund man in the bog,

the wetlands were seen as otherworldly,

sort of like borderland to the beyond.

- [Kavitha] People back then believed that

the Gods controlled everything.

Now that includes the success of their harvest,

and since the bogs produced so much of their food,

they would make sacrifices

to ensure that the God stayed happy.

- [Don] Many scholars see the fact that he is buried

so intentionally in the bog

with his mouth and his eyes gently closed

and his body sort of carefully arranged as eternal rest,

all of these are signs that Tollund man may have achieved

a kind of immortality as a sacred sacrifice to the gods.

- Long before sharks rule the sea,

an even deadlier predator was said to lurk in them.

Then in 1853, chilling proof suggests

that an old sailor legend might just be true.

[tense music]

- As dawn breaks on a small Danish village,

down the beach, the crowd has gathered around something

that has been washed up overnight.

A strange creature lies dead on the sand.

- It's massive.

It has sort of an amorphous blob of a body,

two giant, cloudy eyes,

a bony beak that resembles that of a bird,

and it has 10 long arms with openings that resemble mouths,

with hooked shark teeth.

- [Andrew] To the villagers, this looks like a sea monster,

and to some, it looks like a specific monster,

the mythical kraken.

[dramatic music]

- [Danny] According to legend,

the Kraken is an enormous, multi-armed beast

that has terrorized the ocean for centuries.

It was infamous for smashing boats to pieces

and dragging sailors to a watery grave.

- [Adam] Kraken or not,

the villagers know that this massive carcass

is stinking up the beach.

A few fishermen cut off some pieces to use as bait,

and they bury the rest.

- [Dany] But someone in the village takes a souvenir:

its beak.

- Three years later, the beak is gifted

to a Norwegian scientist, Japetus Steenstrup.

He's fully aware of the stories

about the blood-thirsty Kraken.

- [Andrew] So when Steenstrup gets his hands

on what may be a piece of an actual Kraken,

he realizes he may have the Holy Grail

of maritime mysteries in his hands.

- He immediately notices the similarity

between the beak he's received

and the beak of another animal, a squid.

Squids used their beaks to pulverize their prey

before they eat them.

- [Andrew] The description of the sea monster from the beach

also reminds Seenstrup of squids.

Both have unusually large eyes and 10 limbs in total.

- [Adam] And in certain species, the suckers

have small, tooth-like hooks inside of them

to create a better grip.

- [Austin] Seenstrup declares to the world

that he's discovered a new genus of squid,

Architeuthis, the giant squid.

This takes the myth of the Kraken

and it moves it into the reality of science.

- [Danny] But does one beak in a secondhand story

really prove the existence of a giant killer squid?

The question divides scientists for decades until 1873.

- [Adam] In Portugal Bay, Newfoundland, two men and a boy

are out in a fishing boat

when they spy something floating in the water,

this sort of large, unidentifiable mass,

so they use a pole with a hook on it

to pull the objects closer.

- [Andrew] As the point of the hook pierces the creature,

it roars to life, charges the boat,

and slings a massive tentacle over the side.

- The young member of the fishing crew

grabs their tackle axe and cuts off part of the tentacle,

after which the creature pulls back into the sea.

- [Andrew] The men then bring this 19-foot long tentacle

back to the mainland, and they give it to a local reverend

who has an interest in biology.

- [Danny] Then one month later,

another local fishing boat finds an entire giant squid

tangled in its nets.

The reverend buys the squid for $10

and documents the discovery in a photograph.

- [Andrew] This is the first ever complete specimen

of the giant squid recovered from nature.

It's evidence

that the mythical kraken may indeed be real.

- And it makes you wonder

what other mythical creatures actually exist

in the depths of the briny deep.

- Whether it's a deadly virus frozen in the tundra,

or a secret from the bottom of the sea,

the deadliest discoveries don't just tell us a story,

they warn us of what else may be buried beneath our feet.

I'm Danny Trejo.

Thanks for watching Mysteries Unearthed.