Original subtitles

And they'll drink in a day what Athena's family drinks in a week.

By the time they move on, they've drunk the water hole dry.

Athena's family will use the mud as sunscreen.

And this is vital for the killifish,

for they left their eggs hidden in the mud.

They developed into tiny fish, but never hatched.

They can survive out of water for weeks.

So when Athena's family move on,

they will carry tiny passengers with them.

In this way, the killifish babies get to move between water holes

by riding on elephants.

Athena knows she should have left by now,

but the nearest permanent water is almost 100 miles away.

And she delayed in the hope that Mimi would get stronger.

Mala is now so protective that even Wewe is no longer welcome.

Mimi's big sister, Milly, can give her comfort

but not the milk she so desperately needs.

Only time will tell whether Athena's decision to delay was the right one.

She now has no choice.

The kingdom is without water,

and ahead of them the pools are drying.

They must head for the refuge.

Mala and Milly now work together.

However much Athena might want to,

as matriarch, she cannot put Mimi's needs above those of the whole family.

While Mala and Mimi head down to drink,

Athena will take the others to feed,

for she must try to balance everyone's needs.

Mimi's desperation to drink can only mean that Mala's milk has dried up.

But Mala can't know that.

She knows that a weak calf can easily become trapped in mud,

and her instinct is to do everything she can to keep Mimi away.

Mimi is not yet weaned.

So if she's not been getting milk,

she's not been getting food.

There are times when a mother needs her daughter's support.

It's what family is for.

The next day, it is hotter,

and Athena's predicament, even worse.

She doesn't want to leave Mimi behind,

but neither can she put her entire family at risk.

Athena knows that they've reached the last pool.

And today it will dry.

A terrapin senses it too and will dig deep into the mud while he can.

He'd rather risk being stepped on than caught out by the dry season.

Mala will never give up.

But in the end, Mimi's tiny heart can take her no further.

For a mother, there is nothing worse.

Sometimes, however sad, there is release in death.

But for Wewe, the loss of his friend is especially hard.

Athena knows she cannot afford another delay.

It will take three days to reach the dry-season refuge.

And she has left it so late

that there is nowhere they can drink on the way.

There is no time to stop and comfort Wewe.

Behind them, where there was a water hole,

is now the soft ground that dung beetle's been looking for.

The killifish are but a memory.

Bullfrog will dig down to spend the next months deep below ground.

It's been two months since Stephen hatched.

And the young geese are now fully grown.

They, too, will head for the refuge...

following the same paths as the elephants.

Every day, Athena stops briefly so they can feed.

They are kinder to Wewe now.

Even Princess is more tolerant.

Milly has no milk to give,

but Wewe's suckling will comfort them both.

Athena's route out of the kingdom is a mind map of elephant paths

that she learned from her mother and has never forgotten.

There are badlands to cross.

But they don't walk alone.

All are heading for the refuge.

The refuge is a water hole fed from underground.

Even at the height of the dry season, there is water for all.

Along with the elephants, Stephen's family will be refugees,

waiting here until the rains come and they can all go home.

Athena comes here only in the driest years.

It is the one occasion that her status as monarch is equaled.

This is Satao, king of them all.

A tusker of mythical proportions.

He is a gentle giant...

to whom all defer.

He's been out in the wilderness all year

and will use this occasion to see if any female is in season.

Nusu is a young female from Athena's family.

But she's heavily pregnant.

For the first time since Mimi died, Wewe enjoys himself.

It's a chance for him to meet calves from other families.

And when he's exhausted from playing, there's always his family to help out.

As the dry season progresses, food at the refuge becomes scarce.

So each evening, Athena's family must travel further to feed.

After every journey out, they must all come back to water.

It is their lifeline.

But it ties them to the refuge,

and the knot is slowly tightening.

They have little energy, for almost everything has been eaten.

What started out as a refuge has gradually turned into a prison.

When the rains don't arrive,

what began as a dry season turns into a drought.

And the consequences and casualties start to build.

Athena dares not leave,

for there is no other water within walking distance.

In such a drought, what kills is not thirst but starvation.

For them all, it is only a matter of time.

In her 50 years, Athena has never experienced a drought so bad.

The decision she now has to make has never been more critical.

This time, the lives of her entire family are at stake.

If she stays, they will starve.

But if she leaves and times it wrong,

they will all die of thirst.

Whatever the outcome, the responsibility is hers alone.

Such is their faith in her,

that when she decides to head back to the kingdom, no one hesitates.

For she is their matriarch.

They would follow her anywhere.

Back in her kingdom, it is no better.

Where the water hole was, those that dug down are alive but entombed,

trapped in a state of suspended animation.

For them all, for the spell to be broken,

it must rain.

Out in the badlands,

the family do their best to protect Wewe from the sun.

But he has to walk two steps to their one.

And that takes its toll.

When Athena finally stops,

it's not to look for food but to remember one of their own.

For a few moments, the drought is forgotten

as they join in an understanding of what was

and what it means to be one of their kind.

Where they are heading is still gripped by the drought.

With the kingdom just a day's walk away,

there is only one thing that could cause Athena to stop.

After carrying her baby for almost two years,

Nusu has given birth.

Her baby is a girl.

She knows nothing of what she's been born into.

Her priority is to find her first meal.

As ever, Wewe is eager to make friends.

It would seem the worst time to be born.

But Athena knows differently.

For thousands of years, her kind were thought to be able to summon the rain.

The truth is that she could sense rain coming

when it was over 100 miles away.

There is only one way to rebalance the kingdom.

It's been a year since they saw water flow,

and it comes as a shock.

In Africa, to be born on the cusp of the rains is a sign of good fortune.

For rain is always cause for celebration.

Once again, the elephant paths will channel water to fill water holes.

Underground, the rain is a wake-up call.

Just as every smile leaves its impression on a face,

so every journey leaves its imprint on this continent.

The young geese are still a tight-knit group.

But it won't be long before they start to look for mates of their own.

And true to form, Stephen is last and late.

Tortoise's courtship has been slow and steady,

but he has finally been accepted.

Once again, the water hole will be a lifeline for them all.

For Wewe, there is no place like home.

And there is nothing quite like having a new friend to share it with.

Great droughts bring great rains.

And the kingdom's flush of new growth draws in other families

in a way that hasn't happened for decades.

For a few days, they form a super-herd, 1,000 strong.

The largest gathering of their kind on the planet.

The journey has brought Wewe and Princess together

and has been the first step in acquiring the knowledge

that will help them through their lives.

There will be more droughts to face,

but Athena's family will never forget the extraordinary matriarch

who led them out... and brought them home.

Only a handful of such giant tuskers remain.

Today, this small corner of the continent still belongs to them.

It reminds us of how it once was...

when the whole of Africa was theirs.