(BEES BUZZING)
(SEAGULLS SQUAWKING)
-WILL: This smells terrible. -(CHUCKLES) That's the whole point.
(CHUCKLES)
CRISTINA: Hey, Will, try to put a little muscle into it.
-WILL: All right. -CRISTINA: Give it a good shake.
(WATER RUNNING)
(SUSPENSEFUL MUSIC PLAYING)
-Yeah, I remember this from Jaws. -(CRISTINA LAUGHING)
WILL: Tiger sharks usually spend their lives alone,
wandering the oceans.
But once a year, they mass together near the Great Barrier Reef,
all heading in one single direction.
-Oh, hey. -Mm-hmm. You got one.
Come to us, baby.
Quick, quick, quick.
RESEARCHER 1: Pull it right in. Pull it quick, quick. Pull it right in.
Pull up, pull up. Steady.
Don't let him fight!
Don't let him fight! Don't let go!
(SUSPENSEFUL MUSIC PLAYING)
-RESEARCHER 2: Yeehaw. -I've got you. Pulling him tight.
-Okay, Will. Hang on to that rope. -WILL: Yup.
WILL: These Australian researchers want to track one of the sharks
to find out where they're going.
-RESEARCHER 1: You got her there, Will? -WILL: I'm on the other side.
Yup. Hold the tail high.
That was good, you're secure.
RESEARCHER 2: Watch those teeth.
Watch that, it's still around your leg.
Come on, get that!
-RESEARCHER 1: Ready? -RESEARCHER 2: Yup.
RESEARCHER 1: And rolling.
This one's a, uh... (GROANS)
WILL: He's okay, right? He'll be all right?
RESEARCHER 2: Especially if you start calling her "she." She'll be much better.
WILL: "She?" All right. (CHUCKLES)
Gotta watch the gender pronouns, sorry.
CRISTINA: They don't use hooks, so she's not harmed.
How big is it?
-WILL: Yup. Got it. -What is it?
-WILL: Three point four. -Which'll be about twelve feet.
-All right. -Three-four!
WILL: She's magnificent.
WILL: Now what?
RESEARCHER 1: Uh. Well, we're trying to learn what the sharks are doing here...
'cause we need to know where they go, what their home ranges are,
and then we can follow it via satellite.
We know from the tiding that these sharks are coming
from thousands of miles away.
And we know that sharks follow smells underwater.
So, we know that they're here because they smell something.
WILL: In nature, smell can mean the difference between life and death,
particularly, when you're dealing with sharks.
The question is where are they going and why?
-(EXHALES) -RESEARCHER 1: Your first tiger shark.
Yeah, well...
-I'm not gonna need to do that two times. -RESEARCHER 1: No?
(ALL LAUGH)
WILL: Tiger sharks are so mean that they eat other sharks.
So, getting into the water to photograph one?
That's next level.
-You're good? What do you need? -CRISTINA: My camera.
(SUSPENSEFUL MUSIC PLAYING)
Nothing reminds you of how small and fragile humans are
than being in the water with a tiger shark.
It's not for the faint of heart.
It takes diving into the deep end
and really immersing yourself in their world
to begin to understand these creatures.
Being a wildlife photographer, what I'm trying to do
is paint a picture of our planet.
I try to show what's beautiful and special about nature,
the majesty of our planet and how it supports all living things,
including humans.
(CAMERA CLICKS)
Cristina's coming up.
-WILL: Hey. -CHRISTINA: Hey, Will!
-My camera? -WILL: Uh. Yup.
Did you get the shots you wanted?
-CRISTINA: I did. -WILL: Okay.
I did. I got a great shot of the shark and a shot of you.
Did my face looks too scared?
-CRISTINA: No, you looked good. -I looked good. Did I look strong?
Okay. All right. (LAUGHS)
WILL: The tagged shark goes straight back on track...
like it's locked on course.
Something powerful is attracting them.
But what?
There might be a clue in a smell that takes me right back to being a kid.
WILL: A smell I bet you know too.
Freshly cut grass.
When grass is cut, it releases a scent
that floats straight to the front of your brain...
going to the exact spot where memories and emotions are made.
(GRASS RUSTLING)
WILL: That's why smells can be so vivid...
so powerful.
And cut grass?
That's the smell of summer.
When a caterpillar takes a bite of grass,
it releases that same scent.
And once again...
-(CAWS) -WILL: ...it has an instant effect.
(BIRDS SCREECHING)
-(THRILLING MUSIC PLAYING) -(BIRDS CHIRPING)
(CROWS CAW)
WILL: But now, it's not the smell of summer.
It's the smell of lunch.
Smell is the only sense with no filter.
It's hardwired straight to the brain.
It's just that some of us are better at smelling than others.
CRISTINA: Sharks have a sense of smell that's hundreds of times more potent
and accurate than that of humans.
Such an enormous part of their brain is dedicated to smelling,
to finding their way through the vast expanse of the ocean.
WILL: The shark with the tracker is on the move.
And so are we.
I don't remember anyone in Jaws saying,
"We're gonna need a smaller boat."
(THRILLING MUSIC PLAYING)
CRISTINA: Sharks are coming from all over the place,
and they're all honing in on this particular little spot of land
in the middle of nowhere...
Raine Island.
So what's happening on the island?
That's the next thing that we need to figure out.
What makes this speck of sand in the middle of the ocean so special,
such a mecca for these creatures to be here?
Is that a turtle?
-WILL: Yes, wow. -There it is, there it is.
WILL: Oh, wow.
(AMBIENT MUSIC PLAYING)
WILL: So, they're taking a breath and going down?
CRISTINA: A sea turtle can hold its breath under water for up to seven hours.
So, when you see the same turtle popping its head up
over, and over, and over again...
you know, they clearly are not just breathing,
they're smelling for something, they're sniffing.
Turtles are one of the few animals that can smell both in water and air.
That's why they're popping their noses out.
WILL: And whatever it is that they're sniffing,
it seems to be sending them the same way as the sharks.
WILL: There's one. There's two.
-CRISTINA: Yeah. -WILL: One there.
-CRISTINA: Just look at them. Wow. -WILL: Oh, that's fantastic.
They're all over this place.
-WILL: I see more and more and more. -CRISTINA: Yeah.
(THRILLING MUSIC PLAYING)
WILL: Wow. That is gorgeous.
-WILL: There's a lot of turtles out there. -CRISTINA: A lot of turtles.
So many.
WILL: Can a shark eat a turtle?
Because, I mean, this looks like a turtle buffet.
CRISTINA: You need incredible teeth to munch through that shell.
Tiger sharks are one of the only creatures on the planet
capable of eating an adult green sea turtle.
WILL: But the turtles aren't sweating these sharks one bit.
And the sharks are swimming right on past.
It seems like the turtles and the sharks are being drawn to this island.
-(ENGINE REVIVING) -(BIRDS CHIRPING)
WILL: Raine Island is sacred ground.
If you wanna go ashore, you first have to get permission
from the guardians of the island.
JOHNSON: Hello!
Ma'am. Ma'am.
-CRISTINA: Hello! -FALEN: Ma'am.
Hello. Welcome.
-How are you? -Yeah, good thanks.
-Cristina. -Hello, hello.
-Hi. -Yeah. Welcome.
-Will. I'm good. -JOHNSON: Yeah. Johnson.
-Johnson. -JOHNSON: I'd like to welcome you
to our island.
WILL: And then there's a ritual to help get rid
of any scents from elsewhere.
JOHNSON: Before we allow you, usually you put odor
both on your shoulders and on your head.
-Mm-hmm. -JOHNSON: Yeah. This is to protect you.
-This is like your smell you're giving me? -JOHNSON: Yes.
-Oh, how cool is that. -JOHNSON: Yes, so...
I need all the protection I can get, so...
Yeah.
You know, we're very grateful and very honored for your hospitality.
-Yes. -Thank you so much.
(BIRDS CHIRPING)
WILL: I can't ever remember being in a place
where smell is so important
for humans and animals.
But what signal is it sending out?
WILL: One explorer might have a unique insight.
(SUSPENSEFUL MUSIC PLAYING)
MALE VOICE 1: Left turn!
Paddle.
And right turn. Hold that line. Perfect.
I could do that all day.
WILL: Because Erik can't see,
he relies on smell much more than the rest of us.
ERIK: The wilderness can be such a hostile place.
And I always, as a blind person, thought, "Could I flourish in that environment?"
See, I'm getting a whiff of salmon.
Where there are salmon, there are bears, so heads up.
MALE VOICE 2: Oh, wow. Holy cow. He's looking right at us.
Oh, he knows we're here.
MALE VOICE 2: What should we do?
ERIK: Wow. We should be very quiet. Shrink down. This is their neighborhood.
Let 'em do their thing.
(GRUNTS)
ERIK: When I lost my sight, I started paying attention
to my other senses.
I started recognizing smells that I hadn't noticed before.
I've learned to smell the rain before the drops come.
Or the smell of snow when it's baked by the sun.
Or often, I can recognize trees and plants by their unique scents.
The scent of salmon in the air is so clear to me.
It's a pretty intense smell.
This is how I'm able not just to function but to really thrive in this environment.
(BIRDS CHIRPING)
WILL: Erik can smell the salmon in the water.
But the salmon are smelling something even more extraordinary.
Thousands of rivers pour into the Pacific Ocean.
Somehow the salmon find their way up the right one to the place they were born.
And if you thought the sharks were good at smelling,
these guys are even better.
They can pick up a couple of drops of scent
in one billion drops of water.
(BIRDS CHIRPING)
ERIK: You can definitely tell that we're in the rainforest now, huh?
MALE VOICE 2: Oh, yeah.
ERIK: The musty smell isn't really the trees,
it's more the fungi.
(THRILLING MUSIC PLAYING)
WILL: When we think of fungus, we think of a single mushroom.
But that's just the fruit of something much bigger.
It's like a giant spider web weaving between the tree roots.
The strands connect the forest to such an extent
that the trees can pass water, nutrients, even messages between each other.
(ROCK MUSIC PLAYING)
WILL: Together, they join huge areas of forest
into one single system.
Scientists call it the wood wide web.
So when it rains,
it's not just the smell of the riverbank that's flowing into the stream,
it's the smell of that wood wide web.
A unique cocktail that stays in the salmon's memory.
And guides them hundreds of miles home.
The salmon aren't picking up the smell of their home river,
but the smell of their home riverbank.
But there's no trees on Raine Island.
So, what do the turtles and sharks smell?
Cristina reckons...
we need to get amphibious.
(SUSPENSEFUL MUSIC PLAYING)
WILL: Though, with sharks about, I'm staying near the surface.
CRISTINA: You know, even though it looks like one piece of coral...
each branch is actually made of thousands of tiny creatures...
with its own mouth and tentacles.
But in every creature lives an even tinier algae...
and each of those algae release minute bubbles of aromatic gas.
If you look close enough, you can actually see it.
It's this gas that gives off a unique-smelling fingerprint.
But it is that smell that tells the turtles
that they're approaching land because the coral reef
can only grow in shallow waters.
So essentially,
what is for us the smell of the ocean,
for turtles is the smell of land.
You got it.
-(BIRDS CHIRPING) -(WATER RUSHING)
WILL: When I was a kid, we'd sometimes drive to Atlantic City.
It was exciting to get that first whiff of the sea
and know we were nearly there,
'cause you knew you'd be able to get out of that damn car soon.
That's the incredible thing about smell.
One hint of that scent and I'm remembering my childhood vacations.
But for these turtles, that same smell seems to be about finding their way home.
WILL: There's over one thousand miles of shore here.
We're on the Great Barrier Reef,
the longest stretch of coral anywhere on the planet.
The smell it gives off might get you into the right city...
(SCREECHING)
WILL: ...but it's a different smell that's gonna get you to the right street.
-(SUSPENSEFUL MUSIC PLAYING) -(SCREECHING)
CRISTINA: The only other thing Raine Island is famous for is birds.
And, oh, boy, do they stink.
(QUACKING)
-Very distinct smell, no? -Yeah, that's a very distinct smell.
CRISTINA: That bird smell is a tricky one because it's a cocktail.
It's a concoction of dead fish and poo, and that sea smell,
and it's fresh, and it's also been sitting there for months.
I mean it's, um, it's... it's hard to describe,
but it's, uh, pretty unforgettable. (CHUCKLES)
(BIRDS SCREECHING, CHIRPING)
So all of this back here is the original guano?
-Yes. -WILL: So this is...
tens of thousands of years of birds...
Uh. What's the... what's the scientific word for pooping?
Uh...
-Okay. All right, so... (LAUGHS) -Or uh...
-Evacuating. (LAUGHS) -WILL: Evac... (CHUCKLES)
It just, uh, makes me feel very, very unscience-y.
(BIRDS CHIRPING)
WILL: That smell makes me want to evacuate this island.
But it might be that nasty stink that's bringing thousands of animals in...
(BIRDS CHIRPING)
WILL: So, the turtles smell land by picking up the gases released
by the coral.
And then they hone in on this particular island
because of the smell of the bird...
evacuation.
But why are they coming here?
WILL: Well, there's another underwater animal that can give us a clue.
Just like Raine Island, the coral reefs off Indonesia
are home to a secret gathering.
But not turtles.
On one night in spring,
Palolo worms suddenly start to emerge from the reef.
And as they do, they release a scent.
A fragrance they were born to follow.
Because smell in the natural world doesn't always mean food.
Sometimes, it means sex.
(ROCK MUSIC PLAYING)
WILL: That scent is enough to trigger the worms to release their eggs.
A mass spawning that only happens once a year.
That's what the turtles are up to too.
Coming together to lay their eggs.
CRISTINA: No, there's not a single male turtle on this beach.
-They're all girls. -WILL: Oh, wow.
-CRISTINA: Oh, look at this. -WILL: That's a turtle egg shell.
So, this here is an egg that didn't hatch. You can tell...
-WILL: Oh. -...because it's got all the yolk in.
(BIRDS CHIRPING)
CRISTINA: Because it's leathery.
-It's, uh, porous, so... -WILL: Yeah.
...the baby egg... the baby hatchling inside can actually smell
even while it's in the nest,
and it starts picking up the scent of the island where she was born.
(AMBIENT MUSIC PLAYING)
WILL: The turtles are born here and they lay their eggs here.
But they don't live here.
In fact, they rarely come ashore at all.
For many, it's the first time they've been on land for years.
And, like an astronaut experiencing gravity again,
they suddenly feel their true weight.
All 350 pounds of it.
(BIRDS CHIRPING)
WILL: They struggle up the beach until they're far enough away
from the tide line to dig a nest.
But it's hot.
More than a 100 degrees.
They need to lay their eggs and get back off the beach
before they get baked in the sun.
They have to rush.
And when you rush, one slip...
can have deadly consequences.
She slipped off these rocks here during the night
when she was up trying to lay, so we need to turn her on her side
um, and get righted up. Otherwise, if she stays like this,
she's gonna die during the day with the heat of the sun.
-WILL: And can we help? -Yeah, we'd love a hand.
-WILL: Let's do it. -KATHARINE: Let's dig in
-and help flip her. -WILL: Okay, so we go under.
JOHNSON: Yeah. And be careful...
WILL: Mm-hmm.
...from the flipper, otherwise you're gonna get slapped.
Avoid being slapped. Got it. Never been good at that.
-(CRISTINA LAUGHS) -JOHNSON: So good. (LAUGHS)
-(CHUCKLES) -JOHNSON: So good.
(BIRDS CHIRPING, SCREECHING)
-Be careful. -WILL: Yeah.
Ready. One, two, three, go.
-Hmm. That thing is strong. -(GROANS)
-Whoo! -Yeah, that's why you watch the flipper.
-That's why you were so moved. -WILL: That figures. Okay, yeah.
WILL: (CHUCKLES) Her arm is as strong as mine.
It's like there's almost a... like a baseball bat
in the... in the middle of it.
-KATHARINE: Seriously? -Like that's how strong it feels.
WILL: Without our help, this turtle mom would almost certainly have fried to death
before the day was out.
As many as 2000 die that way every single year.
But not this one.
Not this mom.
She's gonna be okay.
-That was beautiful. -Wow. Wow, she still looks strong too.
CRISTINA: Off she goes. Look at that.
(SOBS) Thank you.
(THRILLING MUSIC PLAYING)
(CRISTINA GIGGLING)
(SNIFFLES)
WILL: That's fantastic.
WILL: Not every story has a happy ending.
That is a horrendous smell.
(BIRDS SCREECHING)
-Oh, wow. This one didn't make it. -Yeah.
(BEES BUZZING)
-Yeah, that's rough. -CRISTINA: I know. She almost did it.
WILL: And you think it's just exhaustion?
She probably got trapped up here, got too hot.
Got it.
CRISTINA: It's over 100 degrees on this beach.
This is one mother who braved everything to lay her eggs,
but she never made it back to the water.
Smells like she's been here a while too.
The good news is that in nature, nothing is wasted.
Right.
WILL: And that's the answer.
That rotting flesh is what the sharks have come for.
They don't want to take on a live turtle.
Those flippers, for one thing.
But they don't have to.
There are plenty of dead ones to eat instead.
Dozens of mothers who came here to lay their eggs,
but died before they could get back to the sea.
All the sharks have to do is wait in the shallows
for the tide to rise.
The smell that draws the sharks here is the smell of death.
(AMBIENT MUSIC PLAYING)
The smell of sacrifice.
WILL: Despite the dangers, any mother that survives
will be back following the scent of the island,
risking their lives once again.
That's the funny thing about smell.
It means different things to different creatures.
Life and birth brings the turtles.
Where we smell bird poop, they smell home.
(CAMERA CLICKS)
Decay is bringing the sharks.
Where we smell death... they smell dinner.
We pick up those same smells.
It's just that we don't truly understand them.
What triggers a nostalgic memory for us might mean life or death
in the animal world.
The smell of cut grass is really a cry for help.
The smell of forest rain is really the smell of fungus.
And the smell of sea is actually the smell of shore.
CRISTINA: You know what's even crazier?
They can remember that exact smell for decades
because they don't come back here until their breeding age,
and that could be thirty years or older.
WILL: Thirty years.
They remember this place from a smell they smelled thirty years ago?
CRISTINA: Do you remember how anything smelled thirty years ago?
-I don't... No. (LAUGHS) -(CHUCKLES)
Uh. Sunday morning breakfast and the smell of bacon frying.
That smell was spectacular.
And I remember my father who was a... a mechanic,
-so he always worked with... -CRISTINA: Ah...
WILL: ...oils and he had, like, a 20-year-old leather key pouch.
The combination of oil and dirt ground into that leather,
I actually used to like the smell.
-What would possess you to smell... -WILL: I never...
-Yes, I remember that. -(LAUGHS)
WILL: More than any other sense, smell is intertwined with our memory
and our emotions.
It's an ancient instinct that's just as powerful today.
It's a universal language that links each and every living thing.
CRISTINA: Come on, little one. You can make it.
Good job, young fella.
But its meaning is personal to you and you alone.
(UPBEAT MUSIC PLAYING)
WILL: More hidden worlds lie ahead.
In the oldest desert on Earth...
I unlock the secret forces...
driving our planet,
the universe,
life,
and us.
MALE VOICE 3: Whoo!
(THEME MUSIC PLAYING)
(THEME MUSIC CONCLUDING)