0:00:31 > 0:00:37The end of the Arctic summer, and the sun hasn't set for three months.
0:00:37 > 0:00:41It's hard to imagine the bitter cold will soon return.
0:00:52 > 0:00:56Some will welcome the chills of autumn, but for most,
0:00:56 > 0:00:59time is running out before they will have to retreat to the south.
0:01:10 > 0:01:13Early autumn in the Canadian Arctic,
0:01:13 > 0:01:16and polar bears are gathering on the coastal strip,
0:01:16 > 0:01:18waiting for the sea to freeze.
0:01:27 > 0:01:29But a life spent alone on the sea ice
0:01:29 > 0:01:33is no preparation for a crowded beach.
0:01:34 > 0:01:37Such close contact with other bears must be stressful.
0:01:37 > 0:01:40Surely tempers will flare.
0:01:46 > 0:01:51Over half a tonne of bear slams into the other.
0:02:07 > 0:02:10Polar bears will fight to the death over mates,
0:02:10 > 0:02:14but not in autumn.
0:02:14 > 0:02:16Now these fearsome predators display
0:02:16 > 0:02:19a surprisingly tolerant side to their natures.
0:02:21 > 0:02:25Being marooned on land means the bears no longer have access
0:02:25 > 0:02:28to the seals they usually hunt
0:02:28 > 0:02:32and they have to scrape by on whatever they can find.
0:02:33 > 0:02:38Like bears the world over, they're not choosy feeders.
0:02:38 > 0:02:40They even turn vegetarian,
0:02:40 > 0:02:44delicately picking out berries from between the thorns.
0:02:53 > 0:02:55There are plenty to go around
0:02:55 > 0:02:59so there's no need to squabble over them.
0:03:02 > 0:03:04Any fighting is just for fun.
0:03:17 > 0:03:22The bears select sparring partners who are well matched
0:03:22 > 0:03:24and they always pull their punches -
0:03:24 > 0:03:26no-one wants to get hurt in a play-fight.
0:03:56 > 0:04:00Perhaps these bouts are a way of testing rivals
0:04:00 > 0:04:04in case they ever meet again out on the sea ice.
0:04:07 > 0:04:09One thing's for sure - the famous loners
0:04:09 > 0:04:13are revealing a social, playful side we rarely see.
0:04:26 > 0:04:30It's all just boisterous fun but with so many big males around,
0:04:30 > 0:04:34the females keep their cubs at a safe distance.
0:04:57 > 0:05:01The wary mother will lead her young to a quieter beach
0:05:01 > 0:05:05along the coast while she waits for the ocean to freeze.
0:05:16 > 0:05:20The sea ice is now at its minimum extent.
0:05:20 > 0:05:24In the Canadian Arctic, vast stretches of coastline
0:05:24 > 0:05:28are now unlocked and ready to receive visitors.
0:05:35 > 0:05:41Belugas - the white whales of the north.
0:05:41 > 0:05:45They're relying on open water to reach an ancient rendezvous.
0:05:48 > 0:05:53It's a journey they make every year along traditional routes.
0:06:20 > 0:06:25Baby belugas ride piggy-back, pulled along by their mother's slip stream.
0:06:28 > 0:06:30This one is only a month old,
0:06:30 > 0:06:33and won't turn white for another five years.
0:06:43 > 0:06:47Thousands of belugas are being drawn to one special estuary
0:06:47 > 0:06:50in the Canadian Arctic.
0:06:59 > 0:07:01It isn't food that brings them here.
0:07:04 > 0:07:07Curiously, it's personal hygiene.
0:07:11 > 0:07:14When the tide is low they swim into the shallows
0:07:14 > 0:07:17and flail around with great enthusiasm.
0:07:27 > 0:07:29They're after a body scrub.
0:07:37 > 0:07:40The gravel acts as a loofah
0:07:40 > 0:07:42and thrashing their bodies across it
0:07:42 > 0:07:44helps to get rid of their old skin.
0:07:47 > 0:07:50Presumably the treatment keeps them clean and streamlined,
0:07:50 > 0:07:53but it also appears to feel good.
0:08:09 > 0:08:11Bliss!
0:08:17 > 0:08:20The water in the estuary is warmer and less salty
0:08:20 > 0:08:25and that seems to soften the skin making the scrub more effective.
0:08:53 > 0:08:58This secluded estuary is only a temporary whale spa -
0:08:58 > 0:09:02the ocean will soon freeze again, forcing the whales to travel south.
0:09:12 > 0:09:17Vast seabird colonies are the jewels of the Arctic.
0:09:29 > 0:09:34Brunnich's guillemots have spent the summer months packed together
0:09:34 > 0:09:37on vertical cliffs beyond the reach of predators.
0:09:46 > 0:09:50They are among the most numerous seabirds in the northern hemisphere.
0:09:50 > 0:09:55This colony alone contains 100,000 birds
0:09:55 > 0:09:58and there are many more like it all along the Arctic coastline.
0:10:04 > 0:10:08In just a few weeks these cliffs will empty
0:10:08 > 0:10:11but before the guillemots can leave, their chicks must fledge.
0:10:12 > 0:10:16Their feathers are now fully formed, but their stubby wings
0:10:16 > 0:10:21are still too short for them to fly properly - this will be a challenge.
0:10:25 > 0:10:31It's a 150-metre drop and they need to make it all the way to the sea.
0:10:33 > 0:10:35Here goes.
0:10:44 > 0:10:47He falls short and survives the crash landing.
0:10:53 > 0:10:57The chicks are manna from heaven for an Arctic fox.
0:11:03 > 0:11:07The next chick is accompanied by a parent.
0:11:18 > 0:11:20Failed again.
0:11:26 > 0:11:28This looks better!
0:11:43 > 0:11:45Success!
0:11:47 > 0:11:49Aquatic landings are certainly gentler
0:11:49 > 0:11:52and foxes can't reach you out here.
0:11:55 > 0:11:59The chicks will stay in their parents' care for another month.
0:12:10 > 0:12:15The guillemots are not the only ones preparing to leave.
0:12:15 > 0:12:19All across the Arctic millions of summer visitors
0:12:19 > 0:12:21are beginning to return south.
0:12:45 > 0:12:48The guillemot chicks can't fly yet,
0:12:48 > 0:12:52so they and their families must swim to their winter feeding grounds.
0:12:54 > 0:12:57It's a journey that will take them a thousand miles south
0:12:57 > 0:13:01to the open ocean and away from the approaching ice.
0:13:07 > 0:13:13The breeding season is over and silence returns to the Arctic.
0:13:21 > 0:13:23But as the first storms of autumn
0:13:23 > 0:13:25sweep through the deserted nesting grounds,
0:13:25 > 0:13:30they bring an unexpected bonanza for the few that remain.
0:13:38 > 0:13:41The discovery doesn't remain secret for long.
0:13:52 > 0:13:55It's a huge fin whale carcass.
0:13:56 > 0:14:00The polar bears have been drawn from several miles away,
0:14:00 > 0:14:03guided by their extraordinary sense of smell.
0:14:05 > 0:14:07Bears are arriving all the time,
0:14:07 > 0:14:12but there's plenty of room at this 18-metre-long dining table.
0:14:17 > 0:14:20They're surprisingly relaxed,
0:14:20 > 0:14:23but with enough for everyone, there's no need to argue.
0:14:27 > 0:14:31The tastiest morsels are often underwater.
0:14:44 > 0:14:48Others prefer some greens with their dinner.
0:15:12 > 0:15:15After a well-balanced meal,
0:15:15 > 0:15:18there's nothing better than some good company.
0:15:37 > 0:15:40Despite their reputation as loners,
0:15:40 > 0:15:44it's surprising just how sociable polar bears can be.
0:16:06 > 0:16:09All across the Arctic the temperature is now dropping
0:16:09 > 0:16:13and the sea is beginning to freeze.
0:16:13 > 0:16:17Every day over 20,000 square miles of ocean
0:16:17 > 0:16:19turn to ice as the cold spreads south.
0:16:24 > 0:16:30At first, a thin, greasy film appears on the surface
0:16:43 > 0:16:46Next, pancakes of ice start to appear.
0:17:06 > 0:17:12The pancakes lock together and form a continuous sheet.
0:17:22 > 0:17:25The Arctic Ocean is freezing again.
0:17:34 > 0:17:41At last the bear family can return to the sea ice where they belong.
0:17:52 > 0:17:57It's been six months since the cubs first emerged from the den.
0:17:59 > 0:18:03They've survived the hazards of melting sea ice in spring
0:18:03 > 0:18:05and lack of food in summer
0:18:05 > 0:18:09and now, at last, they are in their element again.
0:18:14 > 0:18:18As the north of our planet turns away from the sun,
0:18:18 > 0:18:21the big chill travels south.
0:18:27 > 0:18:29Temperatures on the tundra start to fall.
0:18:32 > 0:18:36The shorter days and colder nights trigger a dramatic change
0:18:36 > 0:18:40in the willows and blueberry bushes.
0:18:40 > 0:18:44They stop producing green pigment that harnesses the sun's energy
0:18:44 > 0:18:47and red and yellow pigments build up in their leaves.
0:19:01 > 0:19:07The tundra blazes with colour and the whole landscape is transformed.
0:19:21 > 0:19:27A bull musk ox marks his territory with scent from glands on his face.
0:19:27 > 0:19:30He's preparing for the breeding season.
0:19:32 > 0:19:36He shadows his harem of females as they graze
0:19:36 > 0:19:38the last of the summer grasses.
0:19:42 > 0:19:45He must be on his guard.
0:19:49 > 0:19:51An outsider is arriving,
0:19:51 > 0:19:54a large male whose intentions soon become clear.
0:20:00 > 0:20:03The newcomer circles the resident bull warily.
0:20:05 > 0:20:08The resident must take up the intruder's challenge.
0:20:33 > 0:20:38This clash of polar Titans could easily become a fight to the death.
0:20:50 > 0:20:55The impact is like a car crash at 30 miles an hour.
0:21:17 > 0:21:21A heavy skull and a helmet of horn four inches thick
0:21:21 > 0:21:25provides some protection for the musk ox's brain.
0:21:39 > 0:21:43Over the next half-hour, the advantage ebbs and flows
0:21:43 > 0:21:47as each tries to finish the duel.
0:21:47 > 0:21:51If one can turn the other and gore its flank, the fight will be over.
0:22:01 > 0:22:06The stakes rise as the risk of injury, or even death, increases.
0:22:19 > 0:22:22The rival is outmanoeuvred.
0:22:23 > 0:22:27And the champion returns to his females.
0:22:35 > 0:22:39By now most animals have migrated south, but the musk oxen,
0:22:39 > 0:22:43with their thick coats, will stay and face the approaching winter.
0:22:55 > 0:22:58As autumn progresses, the moisture in the air freezes
0:22:58 > 0:23:01and hoarfrost decorates the leaves.
0:23:32 > 0:23:37Ice crystals grow like diamonds on every twig.
0:23:52 > 0:23:58All across the tundra, both the rivers and the ground freeze solid.
0:24:27 > 0:24:32Glassy cathedrals form as the remaining water
0:24:32 > 0:24:35becomes locked up as ice.
0:24:40 > 0:24:45Soon even the largest waterfalls will be motionless.
0:24:50 > 0:24:54The tundra has been transformed once again.
0:24:54 > 0:24:56It appears deserted.
0:25:02 > 0:25:05Caribou on their migration.
0:25:06 > 0:25:10Unlike the musk ox, caribou do head south for the winter,
0:25:10 > 0:25:12but it's a long and difficult journey.
0:25:15 > 0:25:20They use the frozen lakes as ice roads - these are flat and firm -
0:25:20 > 0:25:24but it seems hooves and ice were never really meant to go together.
0:25:32 > 0:25:36The frisky males would be well advised to keep
0:25:36 > 0:25:40at least one eye on the road as the mating season begins.
0:25:55 > 0:25:59A cow is being closely guarded by a mature bull,
0:25:59 > 0:26:02with his much larger antlers.
0:26:09 > 0:26:11The females are busy feeding up for the winter,
0:26:11 > 0:26:15but the bull has other things on his mind.
0:26:16 > 0:26:19The cow is playing hard to get.
0:26:21 > 0:26:23She heads off with her admirer in pursuit.
0:26:35 > 0:26:37Several other bulls join in the chase.
0:26:50 > 0:26:54She's out in front but the amorous males are gaining on her.
0:27:03 > 0:27:08The big bull breaks off his chase to deal with a rival.
0:27:10 > 0:27:13But now he's fallen behind the other challengers.
0:27:21 > 0:27:24The younger bulls, with their lighter antlers,
0:27:24 > 0:27:26keep up with the cow more easily,
0:27:26 > 0:27:29but as the pace slows, the older bull catches up.
0:27:30 > 0:27:33Again he has to stop and fight.
0:27:59 > 0:28:02A decisive victory for the big male.
0:28:02 > 0:28:06He's earned the respect of the vanquished bulls
0:28:06 > 0:28:08and they now trail in his wake.
0:28:09 > 0:28:14It's now become a game of grandma's footsteps -
0:28:14 > 0:28:20one look from the boss and the young-bloods freeze in their tracks.
0:28:29 > 0:28:34The exhausted bull guards his prize, but he'll need to recover
0:28:34 > 0:28:38before he is able to make the most of his victory,
0:28:38 > 0:28:41and the herd continues its journey south
0:28:41 > 0:28:44to avoid the worst of the advancing cold.
0:28:56 > 0:28:58From the ocean to the tundra,
0:28:58 > 0:29:01the north of our planet is now completely frozen.
0:29:07 > 0:29:09The Antarctic.
0:29:09 > 0:29:13In the far south, autumn can be a particularly savage
0:29:13 > 0:29:15and unpredictable time.
0:29:20 > 0:29:23South Georgia is a splinter of rock in the middle
0:29:23 > 0:29:25of the vast Southern Ocean.
0:29:25 > 0:29:30It's only a hundred miles long and is battered by the elements.
0:29:36 > 0:29:41This ocean generates some of the largest waves on the planet.
0:29:41 > 0:29:44They gain size and power as they travel around the globe,
0:29:44 > 0:29:48uninterrupted by land for 12,000 miles.
0:29:51 > 0:29:55As they buffet South Georgia, they also bring food.
0:29:58 > 0:30:01A seal carcass.
0:30:02 > 0:30:05A prize worth braving the surf for.
0:30:08 > 0:30:11Giant petrels are the vultures of Antarctica,
0:30:11 > 0:30:15and are always the first to the spoils.
0:30:27 > 0:30:31The word is out, and the hordes move in.
0:30:44 > 0:30:48Like feathered dinosaurs, they lock beaks in battle.
0:31:32 > 0:31:37These butchers provide a service for some unlikely meat-eaters.
0:31:40 > 0:31:45With the carcasses now opened, pintail ducks arrive for a meal.
0:31:49 > 0:31:51There's plenty of good food here
0:31:51 > 0:31:56and none of South Georgia's inhabitants can afford to be fussy
0:31:56 > 0:31:58with winter looming.
0:32:04 > 0:32:08After the feast it's time for a rinse and spin.
0:32:19 > 0:32:22The breeding season is finally over
0:32:22 > 0:32:25and the petrels will soon be heading out to sea
0:32:25 > 0:32:28to avoid the worst of the winter.
0:32:34 > 0:32:37A snowstorm is an omen of things to come.
0:32:46 > 0:32:51There is now little left to eat and South Georgia's beaches
0:32:51 > 0:32:54will soon be abandoned to the cold and ice.
0:33:03 > 0:33:06Further south still,
0:33:06 > 0:33:10and the first storms are striking the continent of Antarctica.
0:33:32 > 0:33:35The Adelie penguins must rear their half-grown chicks
0:33:35 > 0:33:39to adulthood before winter hits in just a few weeks' time.
0:33:45 > 0:33:47The chicks are only three weeks old.
0:33:47 > 0:33:50Their downy coats aren't fully waterproof yet
0:33:50 > 0:33:52and they cluster together for warmth.
0:33:59 > 0:34:02These creches are essential during bad weather
0:34:02 > 0:34:04as most of the adults are away at sea,
0:34:04 > 0:34:07fishing for their fast-growing families.
0:34:15 > 0:34:18When the parents return,
0:34:18 > 0:34:22their offspring quickly leave the comfort of their peers.
0:34:27 > 0:34:30Both chicks are ravenously hungry.
0:34:37 > 0:34:40But there may only be enough food for one.
0:34:40 > 0:34:46This race could determine which chick has the better prospects.
0:35:03 > 0:35:09Most Adelie pairs will only manage to raise a single chick each season.
0:35:12 > 0:35:15And this may not be it.
0:35:21 > 0:35:25At least number one is getting stronger by the day.
0:35:31 > 0:35:35With one meal delivered, the parents must quickly find another.
0:35:47 > 0:35:51To rear their chicks before the onset of winter,
0:35:51 > 0:35:53the penguins must work round the clock.
0:36:08 > 0:36:11The parents can travel over 100 miles
0:36:11 > 0:36:14to reach the best fishing grounds
0:36:14 > 0:36:17and may be gone for several days at a time.
0:36:28 > 0:36:31They return with a kilogram of fish and squid in their bellies,
0:36:31 > 0:36:36feed their chicks, and then go off again to repeat the process.
0:36:43 > 0:36:47The job must be finished before the sea freezes over again.
0:36:54 > 0:37:00At seven weeks old, the chicks are losing the last of their baby down
0:37:00 > 0:37:03and are now fully equipped to take the plunge.
0:37:03 > 0:37:06Confidence is all that's lacking.
0:37:08 > 0:37:12Perhaps it'll help if the parents lead by example.
0:37:19 > 0:37:23There...effortless, and as graceful as any fish.
0:37:33 > 0:37:38It seems penguins are not born with a love of water.
0:37:52 > 0:37:56Staying submerged is the next problem.
0:37:58 > 0:38:02Buoyancy control is clearly a skill that needs practice.
0:38:11 > 0:38:14Well, it's a start!
0:38:16 > 0:38:20And at least they can now reach the ice floes.
0:38:26 > 0:38:30Swimming is the first of many lessons.
0:38:30 > 0:38:35They must next learn to recognise danger in all its forms.
0:39:02 > 0:39:04A leopard seal.
0:39:13 > 0:39:16Even high up on an ice floe, the penguins aren't safe.
0:39:18 > 0:39:22Each year, leopard seals will take 5,000 of them
0:39:22 > 0:39:25from this colony alone.
0:39:32 > 0:39:37The Adelies that survive drift out into the Southern Ocean.
0:39:54 > 0:39:58They will spend the next five months feeding at sea,
0:39:58 > 0:40:03avoiding the great freeze that is about to envelop Antarctica.
0:40:17 > 0:40:23The edge of the sea ice advances by up to two and a half miles a day.
0:40:31 > 0:40:35Eventually, over 5 million square miles of ice
0:40:35 > 0:40:38will surround the continent of Antarctica,
0:40:38 > 0:40:40effectively doubling its size.
0:40:47 > 0:40:51The great white wilderness is empty.
0:40:53 > 0:40:55But not for long.
0:41:08 > 0:41:12Bizarrely, it's now that the Emperor penguins arrive,
0:41:12 > 0:41:15just as all the other penguins have left.
0:41:27 > 0:41:30These giants are now at their heaviest.
0:41:30 > 0:41:35They've been feeding at sea all summer and can weigh 40 kilos.
0:41:58 > 0:42:03From the edge of the sea ice, they head towards their colony...
0:42:04 > 0:42:09..but an obstacle course of jumbled ice blocks stands in their way.
0:42:13 > 0:42:17The males are particularly fat at this time of year.
0:42:19 > 0:42:23This will be crucial for their survival in the months ahead,
0:42:23 > 0:42:27but it doesn't make squeezing through narrow gaps any easier!
0:43:02 > 0:43:05With the worst behind them,
0:43:05 > 0:43:10they start a 20-mile march into the freezer to breed -
0:43:10 > 0:43:14the only animals to do so.
0:43:23 > 0:43:28By tobogganing, they can travel at twice their walking speed
0:43:28 > 0:43:31and it takes the weight off tired feet.
0:43:52 > 0:43:56Their destination is the thicker ice, closer to shore,
0:43:56 > 0:44:00which will stay solid long enough for them to safely rear their chicks
0:44:00 > 0:44:02throughout the months to come.
0:44:10 > 0:44:15Their colony is in the lee of icebergs trapped in the frozen ocean
0:44:15 > 0:44:19which will shelter them from the bitter Antarctic winds.
0:44:23 > 0:44:27Newly formed pairs promenade together.
0:44:44 > 0:44:51Courtship demands that both partners strike and hold a variety of poses.
0:44:51 > 0:44:54It's an important process as the bond between the couple
0:44:54 > 0:44:57will have to be an exceptionally strong one.
0:45:08 > 0:45:13The final act lacks the elegance of the prelude
0:45:13 > 0:45:16but at least it's quick.
0:45:21 > 0:45:24The egg is laid a few days later.
0:45:24 > 0:45:28It contains the female's last reserves.
0:45:28 > 0:45:31She now has nothing more to give
0:45:31 > 0:45:34and must pass the egg to the male to incubate.
0:45:39 > 0:45:41The couple must be quick.
0:45:41 > 0:45:45If the egg rests on the ice for too long it'll freeze.
0:45:49 > 0:45:53With their eggs safe in the care of the males,
0:45:53 > 0:45:57the females start the long journey back to the sea.
0:46:09 > 0:46:15The sun is also leaving and will be gone for many months.
0:46:18 > 0:46:21The precious eggs, balanced on the males' feet,
0:46:21 > 0:46:26will make the terrible ordeal ahead worthwhile.
0:46:36 > 0:46:39With no food and only each other for warmth,
0:46:39 > 0:46:43they will attempt to keep the next generation alive
0:46:43 > 0:46:47while surviving in the most brutal conditions on earth.
0:46:50 > 0:46:53Not all of them will succeed.
0:46:57 > 0:46:59At both ends of our planet,
0:46:59 > 0:47:03the sun sets for the last time in autumn.
0:47:05 > 0:47:08A season of change comes to an end
0:47:08 > 0:47:13and one of endless darkness and bitter cold begins.
0:47:41 > 0:47:44The spectacular return of the Emperor penguins
0:47:44 > 0:47:47was a key event for the Frozen Planet team.
0:47:53 > 0:47:55The crew will have to operate
0:47:55 > 0:47:58in the most dangerous of all polar environments -
0:47:58 > 0:48:00the edge of the sea ice.
0:48:01 > 0:48:06They have to fly in everything they'll need for a month
0:48:06 > 0:48:08of living on the frozen ocean.
0:48:11 > 0:48:16On board are slow motion cameraman John Aitchison.
0:48:16 > 0:48:19Underwater cameraman Didier Noirot.
0:48:19 > 0:48:23And director Chadden Hunter.
0:48:25 > 0:48:28With the plane gone, the team are on their own.
0:48:28 > 0:48:31This is home for the next month.
0:48:31 > 0:48:33But it doesn't look like much right now.
0:48:35 > 0:48:38Their tents should be secure on the permanent sea ice
0:48:38 > 0:48:42but they're still miles from the ocean where they hope to film.
0:48:42 > 0:48:44The locals are keen to get acquainted
0:48:44 > 0:48:48with anything of a familiar shape and size.
0:48:49 > 0:48:52The Emperors are welcome neighbours around camp,
0:48:52 > 0:48:56but the team need to film them returning from the water
0:48:56 > 0:48:59and to do that they face a daunting task.
0:48:59 > 0:49:02They must find a path to the open sea
0:49:02 > 0:49:05through a shifting landscape of jagged sea ice.
0:49:06 > 0:49:10Their first scouting trip doesn't look promising.
0:49:10 > 0:49:14Neither maps nor sat-nav help in this ever-changing environment.
0:49:15 > 0:49:19The only clue that the ocean lies somewhere to the east
0:49:19 > 0:49:21is a steady procession of penguins.
0:49:22 > 0:49:26- Any suggestions, Didier? - We must find a way.
0:49:26 > 0:49:29- Yes.- And we will find a way.
0:49:29 > 0:49:33I like the attitude. The penguins have found a way.
0:49:33 > 0:49:38It seems the Emperors will be the key to reaching the ice edge.
0:49:38 > 0:49:39OK, let's go.
0:49:41 > 0:49:43With their penguin guides leading the way,
0:49:43 > 0:49:47snowmobiles are brought in to haul 500kg of equipment
0:49:47 > 0:49:50through the icy maze.
0:49:52 > 0:49:56It's tough going for film crew and penguins.
0:49:56 > 0:50:00When the ice ridges halt progress,
0:50:00 > 0:50:02it's time for some back-breaking work.
0:50:07 > 0:50:12The next three days are spent chiselling through mile after mile
0:50:12 > 0:50:14of broken sea ice.
0:50:27 > 0:50:30Once finally clear of the ice boulders,
0:50:30 > 0:50:35they spot their goal - a patch of open ocean with penguins.
0:50:41 > 0:50:43John is first in position.
0:50:43 > 0:50:47He hopes to capture the most striking images
0:50:47 > 0:50:50by using a computerised slow motion camera.
0:50:51 > 0:50:55But attempts to film the penguins underwater are halted
0:50:55 > 0:50:57by an unwelcome visitor.
0:50:57 > 0:51:00We just saw the head of a massive leopard seal
0:51:00 > 0:51:05so we'll get closer to see what's going on.
0:51:05 > 0:51:09We must be careful because those guys can come out very quickly,
0:51:09 > 0:51:11out of the hole, and give a bite,
0:51:11 > 0:51:15but being red like that, we should be quite protected, you know?
0:51:15 > 0:51:20Being dressed in red may be Didier's idea of safety,
0:51:20 > 0:51:24but the rest of the crew have a healthy respect for leopard seals.
0:51:24 > 0:51:29They can be fiercely territorial and are not afraid to attack humans.
0:51:29 > 0:51:34I think I can run faster than him on land.
0:51:34 > 0:51:36That's very exciting.
0:51:36 > 0:51:40That's the first time I've ever seen a leopard seal in my life
0:51:40 > 0:51:42and he's come straight out of the hole and starts...
0:51:42 > 0:51:45walloping towards us.
0:51:45 > 0:51:47There's a lot of adrenaline.
0:51:47 > 0:51:50With the seal frightening the penguins away
0:51:50 > 0:51:55and hassling the crew, it's time to try a new hole.
0:52:00 > 0:52:03Oh, hello.
0:52:04 > 0:52:06Can you see him?
0:52:08 > 0:52:13While the seal's around, there's little hope of filming the penguins,
0:52:13 > 0:52:17but now a far greater threat is posed by the changing weather.
0:52:18 > 0:52:21That dark headland in the distance is Cape Washington.
0:52:21 > 0:52:25That's our last sign of mainland. We can't see anything else.
0:52:25 > 0:52:27Once we lose sight of that mainland
0:52:27 > 0:52:31that means we're out here on our own on the sea ice.
0:52:31 > 0:52:34This visibility is getting lower and lower.
0:52:34 > 0:52:38It's started snowing and this wind is just blowing offshore
0:52:38 > 0:52:42so, if all this ice heads out, we don't want to be on it.
0:52:42 > 0:52:45I think we're going to can filming for the day.
0:52:50 > 0:52:55All the signs suggest that a big Antarctic storm is on its way.
0:52:58 > 0:53:04Winds pick up to 70mph and everyone retreats to their tents.
0:53:06 > 0:53:09High winds then turn to heavy snow.
0:53:11 > 0:53:15On the driest continent on Earth, a big snowfall is rare.
0:53:18 > 0:53:23White-out conditions take the penguins and film crew by surprise.
0:53:25 > 0:53:29Each day they must dig out their buried equipment.
0:53:29 > 0:53:31Filming has ground to a halt.
0:53:38 > 0:53:43One week and a metre of snow later, the headland is visible again
0:53:43 > 0:53:48and the team are raring to get back to the ice edge.
0:53:49 > 0:53:52They follow their old route back through the frozen maze
0:53:52 > 0:53:55and, with no leopard seal in sight,
0:53:55 > 0:53:58it's time for another attempt with the pole cam.
0:53:58 > 0:54:03It's cumbersome, but it allows the team to capture underwater images
0:54:03 > 0:54:06without having to risk the icy water themselves.
0:54:10 > 0:54:14- That is OK?- That's perfect. - They are coming. I can see some.
0:54:14 > 0:54:16Oh, wow!
0:54:16 > 0:54:20Penguins coming in the hole. This is awesome. This is great.
0:54:20 > 0:54:25The aim now is to film the penguins' dramatic exit from the hole.
0:54:25 > 0:54:28The only problem...which hole?!
0:54:37 > 0:54:40These penguins keep outsmarting us.
0:54:40 > 0:54:43We tried to switch holes to film them coming up
0:54:43 > 0:54:46and they all just completely came up behind us.
0:54:46 > 0:54:48Whatever the crew try,
0:54:48 > 0:54:52there's always someone who hasn't read the script!
0:54:53 > 0:54:58John has been filming but he can't view his slow-motion shots
0:54:58 > 0:55:00until they're downloaded to a computer.
0:55:01 > 0:55:05While he waits, Didier seizes his chance.
0:55:05 > 0:55:07Come, my friend. Come.
0:55:07 > 0:55:10If you can't beat them, join them.
0:55:10 > 0:55:14It's time to go scuba diving in the coldest waters on the planet.
0:55:14 > 0:55:17I will see you on the other side.
0:55:23 > 0:55:25The team are 300 miles from help
0:55:25 > 0:55:29and have only a small hole as their lifeline to the surface.
0:55:34 > 0:55:36A magical world opens up.
0:55:36 > 0:55:38For the first time
0:55:38 > 0:55:43Didier now shares the penguins' perspective from beneath the ice.
0:55:58 > 0:56:02This is Antarctica at its most enchanting.
0:56:04 > 0:56:06For Chadden, after weeks of struggle,
0:56:06 > 0:56:10the sequence quite literally falls into his lap.
0:56:10 > 0:56:12Whoa!
0:56:13 > 0:56:15Sorry!
0:56:16 > 0:56:18I think I'm in the way.
0:56:25 > 0:56:28Just come a little this way. There we go.
0:56:32 > 0:56:34I'm getting run over by penguins!
0:56:36 > 0:56:40I think it worked. It's very difficult to tell.
0:56:40 > 0:56:41John's camera is finally capturing
0:56:41 > 0:56:47the super-slow-motion images of the Emperors' dramatic return.
0:56:49 > 0:56:52With the penguins performing perfectly,
0:56:52 > 0:56:54it was all falling into place.
0:56:54 > 0:56:56The team were finally able to capture
0:56:56 > 0:57:00Antarctica's most spectacular belly flop.
0:57:29 > 0:57:32Subtitles by Red Bee Media Ltd