A sperm whale lies stranded, close to death.
To look at him now, it's hard to imagine what an extraordinary life he's led.
This is the largest predator the world has ever seen.
His home is the abyss.
He's spent most of his life at a staggering two kilometres below the waves.
Only surfacing to breathe.
Our technology can only ever give us the briefest glimpse of his alien landscape.
But what if we could see it as he sees it?
It would be like turning on the lights in a world of eternal darkness.
Down here, mountains rise higher than Everest,
ravines run deeper than the Grand Canyon
and the creatures
are more monstrous than anything found on land.
This film lights up the deep.
It tells the story of one whale's 80-year journey
from calf to king of the abyss.
Welcome to the ultimate ocean odyssey.
November, 1929, and a steam ship is working in the North Atlantic,
200 miles off the coast of Newfoundland.
The crew are on a mission to repair telegraph cables
that run along the ocean floor between Europe and America.
The cable lies in a world that these men know little about.
Although they cannot see it,
they are floating above a giant deep-sea cliff.
Here, the continental shelf drops away to depths of over four kilometres.
These are the fertile fishing grounds of the Grand Banks.
Not far away, a sperm whale is about to make his first deep-water dive.
He's only two years old.
Until now, he's spent his young life in the sunlit surface waters
under the protection of his huge mother.
This is the first stage of an apprenticeship
that will take him deeper and deeper into the oceans of the world.
At 400 metres, the young bull enters the midnight zone.
Down here, no light remains. His eyes are useless.
But he isn't blind.
He uses sound to see into the gloom.
A third of his body is given over to the most powerful sonar in the natural world.
His giant nose fires clicks into the depths.
The echoes bounce back from more than a kilometre away,
illuminating the hidden world.
The perilous slopes of the Grand Banks.
This is the gateway to the abyss.
Down there is a world of astonishing landscapes and monstrous creatures.
These slopes drop for a further three kilometres
to where the pressure is 300 times what it is on the surface.
He's reaching his limit.
His young body would be crushed at those depths,
but his mother and the other females that make up his family pod
have no such restrictions.
As they head for their hunting grounds, their bodies disturb tiny marine creatures
leaving a bioluminescent trail in their wake.
One of the females stays behind to baby-sit the young bull
as he explores this unfamiliar world.
The Grand Banks are the submarine equivalent to Alpine slopes.
And like the Alps, they're covered in snow.
But this is marine snow.
Made up of tiny fragments of dead fish and plankton,
it falls from the fertile waters above,
balancing precariously along the edge of the steep slopes.
Most species of whale survive grazing on tiny plankton,
but sperm whales use their sonar to hunt down the creatures of the deep.
The young whale is investigating something twitching on the sea bed.
But this disturbance is man-made.
Keep the tension!
By the 1930s, dozens of massive telegraph cables
crisscrossed the floor of the Atlantic.
It's one of mankind's first attempts to exploit the deep,
and they require frequent maintenance.
Dragging the cables up from the bottom, they're looking for signs of damage.
Every year, cables are mysteriously broken.
Today they'll learn the landscape below them is not nearly as dead as they think it is.
In the total darkness of the abyss,
the whale's echolocation picks up the moving form of the cable.
The young female's curiosity is leading her into trouble.
In the early evening, a deep-ocean earthquake reverberates along the Grand Banks.
It measures 7.2 on the Richter scale.
For the abyss, it's a small tremor
but it will spark off a deadly chain of events.
The bull's mother can hear the disturbance.
The young whale must leave, but his companion is caught up in the coils.
And now everyone's in danger.
The earthquake has set off a giant underwater landslide.
Along the banks, an area half the size of Holland is on the move.
The young bull is forced to leave the female to her fate.
The sea seems to take a giant intake of breath.
A tsunami radiates across the ocean at 300 kilometres an hour.
For the crew, the giant wave causes little more than a lurch.
In deep water, the men are safe.
But the wave is heading towards the Newfoundland coast.
For generations, these people have harvested the shallow waters of the Grand Banks.
Today, though, they'll learn that events in the abyss
can reach out and change their lives.
Come on. Walk on.
In the shallows, the wave grows.
It's the most destructive Atlantic tsunami for 100 years.
No family on that coast was unaffected.
The secret world of the abyss can never be taken for granted.
Twelve transatlantic cables snapped across 800 kilometres of seabed.
And the breaking signals provided the first clear record
of the geological forces at work beneath the sea.
That one's nearly as big as you, Bob.
It's not the only thing that these cables can reveal about the deep.
Deaths of whales caught like this provide the first proof
about just how deep sperm whales can dive.
The young bull has started out on his journey of deep-sea discovery.
And so has man.
Look at the size of this one.
Have you got your rod, Bob? Yeah, somewhere.
For an adult whale to reach 45 tonnes,
it must eat an average of 1,000 kilos of food a day.
An appetite which drives an endless search for enough food.
And as the pod turns east, another impulse gives urgency to their travels.
The young bull's mother is pregnant.
It's time to head for their birthing grounds in the heart of the Atlantic.
At the foot of the continental shelf
lies the flattest and stillest place on Earth.
It's called the abyssal plain
and stretches out ahead of the whales for 4,500 kilometres.
It's like a giant desert.
Down here there's no hard surface for life to gain a foothold.
Life in the abyss only gathers where the currents and seabed help circulate nutrients.
This is no place for a giant predator like a whale.
They're in for a long, hungry trek.
Day and night they move over the ocean desert, heading for the next feeding station.
The next island of life.
But there is one creature that is drawn to these lifeless plains.
Emerging from ponds all along the coast of America,
every year, over a million eels head for one of the most extraordinary gatherings on Earth.
The abyssal plain is their destination.
In these vast mating balls, eggs are fertilised en masse.
The frenzy marks a macabre climax to the adults' lives.
For one day every year, the dead zone is littered with a million corpses
and billions of eggs.
Everything that falls to the bottom of the ocean will eventually be recycled.
The nutrients brought back to the surface fuelling the world's largest food chain.
And the sperm whale sits at the top of that chain.
They are the apex predators.
But for this pod, it's been a week since they filled their stomachs.
And as they get all their fresh water from the food they eat,
if the young whale doesn't feed soon, he'll die of thirst before he dies of hunger.
But hope rises out of the gloom.
The mountainous form signals that they're reaching the end of their ordeal.
In the deep ocean, any hard structure creates a haven for life
and a hunting opportunity for sperm whales.
The giant peaks of this mountain range lie a thousand metres below the surface.
Almost double the distance the young bull managed at the Grand Banks.
Dive too deep and he could drown before he gets back to the surface.
But if he stays up here, he will starve.
It will take over 20 minutes to reach the hunting grounds below.
Instinctively he settles into a dive rate of five kilometres an hour.
He's falling into the abyss.
His heart rate slows to one beat per minute.
Blood supply to his skin is cut off to prevent heat loss.
And as the pressure increases, his ribcage is designed to collapse.
The lungs have flattened under the crushing body.
Protective mucus is needed to keep them from sticking together permanently.
Although his destination is still hundreds of metres below him,
his powerful sonar sketches the landscape.
Ahead of him lies one of the strangest worlds in the abyss.
Lost City.
Here, vents of super-heated water have been flowing for 30,000 years,
depositing minerals that grow into giant spires,
some of them 60 metres high.
The deep shapes the creatures that live here.
Sometimes into bizarre forms.
An oarfish can grow to the size of a two-storey house.
It's the longest fish in the sea.
Almost never seen at the surface, rare sightings of this creature
sparked legends of man-eating serpent sea monsters.
In fact, their prey is tiny.
They're opportunist predators that suck up a passing morsel with an extendable mouth.
Humans will not discover these ghostly spires for another 70 years.
Whales have known about it for generations.
After his marathon descent,
the young whale has less than 10 minutes at the bottom.
Using sonar, he searches the new world for potential food.
The juvenile has no teeth.
Sperm whales suck in their prey, crushing it in their stomach.
The spiny oarfish is the wrong choice.
Following his mother's lead, he's starting to get the idea.
An adult whale can eat 500 squid in a single dive.
The young bull is running low on oxygen.
And the surface is 20 minutes above him.
His first encounter with one of the greatest landscapes of the deep
has been all too brief.
Lost City sits on top of one of the biggest seamounts in the Atlantic,
Atlantis Massif.
This, in turn, hangs on the edge of one of the greatest canyons in the ocean,
part of a giant mountain chain
that the young whale will learn is a lifeline for his kind.
When your world is this vast, the deep ocean is a daunting place.
Alone on the surface, he uses his sensitive hearing
to listen to the sounds of the ocean.
He tracks the clicks of his mother, following her as she hunts deep below.
There are other sounds in the ocean.
There are animals out here that will eat a young whale.
And as the female returns to the surface,
she will fall silent for over 20 minutes.
It's a long wait.
Their reunion is short-lived.
When food is available, whales rarely spend more than 10 minutes on the surface.
The huge mountain chain beneath them is the Mid-Atlantic Ridge.
It's a highway of life that will guide the whales to their birthing grounds in the north.
Stretching from the Southern Ocean to Iceland,
this ridge is part of the greatest geological feature on the planet.
Formed by the moving apart of the Earth's crust, two plates slowly separate
and lava oozes from the Earth's mantle, building a giant ridge of undersea mountains.
And as the ridge turns east, they rise higher
until the tips of six volcanoes break out of the water
forming what we call the Azores.
These steep volcanic cliffs channel deep-water currents
carrying nutrients to the surface.
In the shallows, life abounds and the food chain continues down into the abyss.
In the inky blackness of the deep,
life is marked by the sparkle of bioluminescent creatures.
And if we could see the extent of these glowing shoals,
they'd appear like a glittering firework display.
These chemical glows are used as lures and decoys to confuse the enemy.
But the enemy uses it, too.
The anglerfish looks terrifying.
In fact, it's not much bigger than your hand.
Most predators here are squid
and they come in all sizes.
The giant squid is bigger than a family car.
Its eye is the size of a basketball.
No one has ever witnessed the giant squid in the deep.
And despite its size, it's a favourite prey of the sperm whale.
The battle between them is the greatest wildlife spectacle
that we've never actually witnessed.
As the pod approaches the Azores, they encounter an unexpected obstacle.
Although we never see it,
hidden in the depths of the abyss, there is a volcanic eruption everyday.
As the broiling lava hits pressurised seawater,
hot gases are trapped in the honeycomb of solidifying rock.
For a moment, gas-filled boulders float.
The whales have arrived.
This is their haven.
In the 1920s people had very little idea
about what these animals got up to below the surface.
It would be decades before we learn
that sperm whales are the most social of all the whales.
And at gatherings like this, their sonar changes into a complex pattern of clicks,
almost a language.
Hardly surprising from an animal with the biggest brain on the planet.
For the young whale, it's an opportunity to reinforce his bonds with the pod,
so vital to his survival in the open ocean.
But even here, danger is never far away.
In New Zealand, the scars on the dying bull
are testament to battles with all kinds of ocean creatures.
Look at these marks.
And even 80 years on, a large chunk out of his tail
bears witness to a moment in the Azores that could so easily have cut short his life.
While the rest of the pod heads down to feed in the volcanic depths
the bull's mother does not join them.
The pangs of labour have started.
The young bull stays on the surface with her.
A team of killer whales have been following the social chatter of the sperm whales
for several miles.
If they isolate the young whale, they'll eat him alive.
The pack switches to radio silence.
Two orcas peel off. They will close in from behind.
Travelling at 35 knots, a killer takes a bite of flesh in less than a second.
Now there is blood in the water and the frenzy begins.
The mother tries to put her body between the injured calf and the killers.
Far below, the pod hear the orcas. They must return before it's too late.
The pod arrives, but the danger is not over.
They instinctively form a protective rosette around the injured calf.
But the killer whales are relentless.
They can kill an entire pod.
But not today.
A fully-grown bull has arrived.
Male sperm whales are 30% larger than females
and carry over twice the weight.
Unlike the females, they possess a formidable row of teeth.
He's one whale too many for the killers.
For the first time, the young whale meets the giant he will one day become.
His life is already changing.
In the centre of the melee, his mother has given birth.
A tiny sister.
The young bull will no longer have the constant protection of his mother.
He will have to start to face up to the dangers of the deep on his own.
For decades, sperm whales have provided us
with our most important clues to life in the deep oceans.
Scars on their body and the contents of their stomachs
reveal how giant sea creatures, thought to be part of mythology,
do exist after all.
Keep him wet.
As scientists slowly piece together a more detailed picture of this animal's world,
they're also beginning to understand the complexity of the oceans themselves.
He's still alive, all right.
And how these giant bodies of water are the engine of the world's climate.
It's 1938, and a storm is brewing in the mid Atlantic.
Most of the sun's energy is stored in the sea.
Just the top three metres alone absorbs more heat than the entire atmosphere of the Earth.
Ocean currents distribute this heat slowly around the planet.
As the warm seas evaporate, huge quantities of water are carried high into the atmosphere.
A small shift in the heat of the ocean can set in motion a weather pattern
that grows to massive proportions.
The young bull is 12 years old.
A 35-tonne teenager as big as a bus.
The pod's heading back along the Mid-Atlantic Ridge.
Over time, adult whales build up
astonishingly detailed mental maps of the deep oceans.
Together with their long range sonar, they are phenomenal navigators.
The search for food never ends.
In one life time they will travel over half a million kilometres.
The bottom here is too deep to hunt,
so the mother is searching for changes in the water currents that will lead her to food.
They're invisible to human eyes,
but a sperm whale can sense the change in temperature.
Where the warm waters of the Gulf Stream rub along the cold, still waters of the Atlantic,
an ocean front is created.
Huge eddies form, called gyres, which can grow to many kilometres across.
The upwelling draws nutrients towards the surface, creating blooms of plankton,
sparking off a temporary island of life.
First on the scene, fish gather in massive shoals.
They, in turn, attract the blue-water hunters.
Bait balls are corralled by dolphin and marlin,
shark and tuna.
It's a busy oasis in an otherwise empty stretch of ocean.
In the depths, squid get lured up towards the action above them.
It's a niche only the whales can cash in on.
But not all the predators are below the water.
In the 1930s, steam-powered whalers are state-of-the-art hunting machines.
For over a century, the sperm whale has been the most valuable of all the whales.
Over a third of the whale's volume is oil.
Its famous nose carries 150 gallons of it.
It's used to lubricate delicate machinery
and to the whalers, it's literally worth its weight in gold.
To find their quarry, they've also learned to read the movements of the ocean.
Like the whales, they know that an abrupt change in sea temperature is a clue to an ocean front.
Find the front and you'll find fish.
Find fish and there's a good chance you'll find whales.
They're not far behind the pod now.
But unknown to them, they are, in turn, being chased.
Fed on the warm waters of the Gulf Stream, the storm has been growing.
As the moist, warm air rises, cooler air is sucked in.
The more water that is drawn up, the more powerful the storm becomes.
The rotation of the Earth causes the clouds to twist,
and the familiar shape of a hurricane has started to form.
Three hundred kilometres to the north,
the whales have arrived above a spectacular canyon system
that cuts across the Mid-Atlantic Ridge.
The Charley Gibbs Fracture Zone.
Here, halfway between Iceland and the Azores,
two massive fractures funnel deep-ocean currents in different directions.
The amount of flow through here is the equivalent to all the rivers on Earth.
It's one of the most abundant deep sea worlds in the Atlantic.
The adults waste no time in diving down.
But the young bull stays on the surface to prepare himself.
This will be the deepest dive of his life.
Thirty minutes down and his mother has made it to the edge of the Fracture Zone.
Some of these trenches are three times deeper than the Grand Canyon.
It will take all her skills to navigate these dark passages.
Below a depth of two kilometres,
only about 5% of the creatures are known to us.
But they are all potential prey for a whale.
A wreckfish is also attracted by the life that clings to the canyon wall.
These deep-water scavengers grow to over a metre.
But the sperm whale is not the only giant predator down here.
The giant squid is the stuff of legend.
A lacerating beak feeds prey down a throat that travels directly through its brain.
Coordinating eight arms with precision
takes one of the most advanced nervous systems in the world.
Giant squid are never seen on the surface alive.
In the deep, these solitary creatures are not as rare as we once thought.
The young bull has finally made it to the canyon,
but he's at the limits of his endurance.
He will stay near the top of the ridge just where the giant squid likes to forage.
The adults have already returned to the surface.
Parking up for a snooze after their big meal.
Their giant nose causes them to float upright,
allowing the blowhole to sit just above the surface.
Deep below, the young bull is still hunting through the labyrinth of canyons.
He's spotted a shape in the murk.
It's bigger than anything he's eaten before.
The squid can feel the whale's sonar but has no way of locating its directions.
The whale needs an element of surprise.
But a sudden flash from a shoal of bioluminescent shrimp gives him away.
The great battle begins.
On the surface, the party's unaware of the plight of the teenager below them.
If not handled right, a giant squid can inflict real injuries on a young whale.
Suddenly they're in mortal danger, too.
The whales instinctively dive but they've not prepared their bodies to go deep.
They can stay under for no more than ten minutes. The trap has been sprung.
Deep below, the squid is wrapped around his head.
Serrated suckers cut into his skin.
And he's running low on oxygen.
Starboard! Full starboard!
The adults are also running out of breath.
As the young bull heads for the surface, the squid momentarily releases its grip,
and the whale seizes his chance.
But the writhing mass of tentacles is still alive. The whale needs to kill it inside his stomach.
Sucking the squid down into his throat,
powerful muscles squeeze the life out of the squid.
The biggest predator on the planet has triumphed over one of the greatest monsters of the deep.
But he does not know the storm that awaits him on the surface.
As the whalers set out for home, the power of the ocean is about to be unleashed.
120 kilometres an hour winds whip up 20-metre waves.
When these waves hit currents moving in the opposite direction,
they're magnified into seven-storey peaks.
If the boats get caught side on, they'll capsize.
Both ships must head directly into the waves.
The bull snatches a much needed gulp of air.
The power of the storm can still be heard
to depths of over 500 metres and the noise creates a cacophony.
If the swell is big enough, even a 100-foot boat will fall down the side of the wave.
Once side on, the end is all too quick.
If a body is held deeper than 70 metres, it will never return to the surface.
The abyss claims all who come this close.
In the calm after the storm,
it's hard to appreciate the fiendish strength of what has been and gone.
It's ripped across all current boundaries.
The low pressure mixing up parts of the ocean
that do not usually have any disturbance from below.
It's travelled through the oceans like a forest fire, destructive and awful.
But the turmoil will stimulate new life.
In a matter of months,
powerful urges would have driven the teenage bull to leave his family.
But not like this.
He is prematurely alone,
and the biggest brain in the animal kingdom cannot be unaffected.
This orphan is yet to become king of the deep.
Next week, we find out how the whale survives
the most perilous deep-sea landscapes of them all.
And these aren't the only dangers he'll face.
As time moves on, his world is changing.