The BBC's Feargal Keane writes a diary of a week with Kenya's nomadic Turkana people and how they cope with the effects of severe poverty and relentless drought.
DAY ONE: SENSE OF DREAD
I am leaving for Africa again. I hate saying goodbye to my family.
I will only be gone a week, not like the old days when trips stretched on interminably.
But in the hour before departure I feel a looming sense of dread.
Feargal Keane helped the Turkanas fetch water
But enough whining - this is the best job in the world. I am being paid to travel to a distance place and explore an ancient culture.
On the plane I bury myself in reading about the Turkana. The research tells me they are nomadic pastoralists who migrated from what is now Uganda several centuries ago.
There are roughly 250,000 of them and they are organised into clans. The clan "brand" - a mark cut into the body - is the most important symbol of Turkana identity.
For the Turkana - as with other pastoralists - their herds are the definition of family and individual worth. Now because of drought and the effects of Kenya's endemic corruption, their way of life is under siege.
DAY TWO: GRIM CAPITAL
The familiar arrival at Nairobi. The passport control people are friendly and efficient. A pleasant change from long ago when surliness was the order of the day.
After a few hours I am in the air again. We fly from Nairobi's Wilson airport in a charter plane just about large enough to calm my fear of flying.
The journey is sublime. We fly over the great volcanic bowl of Mount Longonot and over the glittering stillness of Lake Naivasha before the plane begins its descent into the sun blasted plains of Turkana.
Below we can see abandoned villages and the ghosts of rivers. An occasional herdsman appears with his camels and goats, lost in the immensity of a land where the horizon melts in the heat haze.
We land on a rough strip in the town of Lodwar, the grim capital of Turkanaland.
I greeted the dawn with hollowed eyes and weighted limbs.
DAY THREE: DELAYED WEDDING
We set out across the plains from Lodwar. By 0800 the sun is already high and the temperature creeping into the 30s.
There is a long hard drive ahead to the village of Kaeris, our first port of call.
The British aid agency Oxfam, which has been working here for years, agrees to help us and has told villagers that we will be coming.
"They were planning a wedding and have delayed it for your arrival," says Bea Karanja, an idealistic young Kenyan working with Oxfam.
I know that we cannot live as the Turkana live. Even the fittest westerner would struggle on the amount of food and water they consume every day. And I am emphatically not the fittest of westerners.
I know that to western eyes I look ridiculous, the sort of plump and sweating white man whose inane grin has stared out from photographs of Africa for many a long year
But we have a chance to observe their lives from close quarters and to hear their stories over several days.
Arriving in Kaeris we are greeted by the most extraordinary scene. Hundreds of tribal women, garlanded in animal skins and wearing feathers and bright beads, sing and dance as our car pulls into the village.
I am handed a spear, a stick and the other accoutrements of the Turkana elder, then beads and a headdress.
I know that to western eyes I look ridiculous, the sort of plump and sweating white man whose inane grin has stared out from photographs of Africa for many a long year.
But the honorary investiture as an elder is an act of great generosity from the Turkana and in that spirit I march, spear in hand, across the hot ground to watch the last of the wedding bargaining and the final joyous coming together of the two clans over a feast of camel meat.
That night we bed down in the open near the home of Kevina Esinyan, who has been single-handedly taking care of her five children ever since being abandoned by her husband.
The word brave doesn't do justice to her. I go to sleep to the sound of the men still singing and dancing as the wedding celebrations continue.
DAY FOUR: SENSE OF BELONGING
To the water pump with Kevina. It is hot, heading for the mid-30s, despite the fact that it's still only around 0900.
She does this journey three times a day, roughly 1km each way from the entrance to her hut.
Many of the fishermen on Lake Turkana are former pastoralists
Better than the old times, she says, when they had to walk as much as 18km for water. I find even the short journey hard work. Kevina is untroubled.
Kevina is being assisted by Oxfam's Cash for Work programme under which the most vulnerable families in the community are given small cash grants to start businesses.
Kevina used the money to open a small shop. With the profits she can buy food and school uniforms for her children. The scheme plays to the Turkana's great strength of self reliance.
That afternoon we drive in the direction of the Ethiopian border, a grinding and dusty progress along dried out riverbeds which ends at the foot of a range of mountains.
We are greeted by an old chief who is sitting under an acacia tree with the other men of his clan. Chief James is 71 and has eight wives, 20 daughters and 15 sons. He has roamed the plains for 70 years.
Watching his third son Loweton come down from the mountains with the livestock I feel an urgent sense of loss.
Perhaps it is the near perfect nature of the scene, a people immersed in a sense of belonging that has been lost in so much of the West, the children playing among the straw huts, the sound of camel milk splashing into wooden containers as the women milk the herd. Soon enough, I thought to myself, it will be gone.
DAY FIVE: CHANGED CULTURE
We drive on and bounce over more appalling dirt tracks. My back and head ache. I feel every one of my 45 years.
But by early afternoon we reach the shores of Lake Turkana. Cool breezes and the sound of water are balms to our exhausted bodies.
Life on the margins is becoming increasingly untenable
We camp in the shade of some thorn trees alongside a group of fishermen. They are all former pastoralists who have diversified.
Once upon a time this would have been unthinkable. In a culture where a warrior was defined by the size of his herd it was seen as unmanly to cultivate or fish. But the age of hunger has created a powerful impetus for change.
Out on the water with Dominic Alim and his brothers I watch them haul in net after net.
I am fond of the water as a rule but this is hellish. The sun beats on my skull relentlessly. The motion of the boat makes my stomach churn. And at my feet fish flap mournfully. I cannot reach the dry land soon enough.
But that night we feast on fish roasted over an open fire and as the wind comes up I look at a night sky more perfect than any I can ever remember seeing.
DAY SIX: HUNG OUT TO DRY
We are up at dawn. There is no option really. Once the sun comes up behind the lake the shore is flooded with light. People are on the move and it is impossible to sleep on. We watch a group of women gathering on the shore. They start to dance and sing.
"They are wishing the fishermen well," explained our driver, John. Darren is at the shore taking shots of the men as they work on mending nets.
When the fishermen come back the women are there waiting. Some are wives, sisters or daughters. They help to scale and gut the fish. I notice that the liver and other offal is placed in a bucket.
When our light plane flew out of Lodwar I found myself doing what the Turkana do every day - looking at the dried-out land below I prayed for rain
"They will use that to make oil," said John.
Nothing is wasted here. Because there is no freezing facility most of the fish is hung out to dry. The stink is appalling.
That night around the fire I eat from the communal pot with Dominic and the other fishermen.
They ask me about Iraq: "Why are people fighting?"
Some of them believe the steadily heating climate is being caused by the war.
Others want my assurance that the killers won't come to Lake Turkana. They have already experienced violence in clashes with Ethiopian fishermen over control of parts of the lake.
DAY SEVEN: ABANDONED FISH PLANT
We strike camp. People from all along the shore come to say goodbye.
They also come to see what we might be leaving behind. Plastic bottles, clothes, spare foodstuffs are all gathered up and shared out by the older members of the group.
We had been treated to their hospitality and we had taken up their time with endless questions. It was only right to repay that kindness in whatever way we could.
We drove up the lakeshore to the village of Kalekol to visit an abandoned fish processing factory, the Norwegians built in the great days of big bilateral aid programmes.
But it is empty now, victim to poor planning and consultation and political interference. A local man told me the Norwegians were given 48 hours to get out after their government gave political asylum to a Kenyan dissident. That was back in the days of the venal Moi regime.
Things are little better now. A former British ambassador accused the current government of "vomiting on donor's shoes", so appalled was he at the scale of the corruption.
The fish plant was a depressing last stop in Turkanaland but probably the right place to conclude.
There is no happy ending to the story of the Turkana. They have long lived on the margins, a way of life that was manageable as long as the rains were regular. But with relentless drought the margins are coming close to being impossible.
When our light plane flew out of Lodwar I found myself doing what the Turkana do every day. Looking at the dried-out land below I prayed for rain.
Fergal Keane and Darren Conway's film - Nomads Of The Shore - will be broadcast on BBC News24 this weekend.