Gordon Brown has visited Africa to highlight poverty issues. The BBC's political correspondent, Mark Mardell, travelled with the chancellor. Here is his diary, starting with his end-of-trip verdict.
Returning to UK
The memory Gordon Brown says keeps returning to him - the one that he says is burnt into him - is that of a 12 year-old girl, whose parents died of Aids, and who is HIV positive herself.
Gordon Brown, pictured in Tanzania
Mr Brown seems haunted by her eyes, desolate of all hope.
And then he talks of those eyes that do inspire optimism: an extraordinary performance by schoolgirls of Kenya's largest slum, advancing with crowded menace, flicking their hips in a manner almost as disturbing, before the finale of a clenched fist salute and shout of "free education - free education for all".
Mr Brown's message generally, that compassion must become action before that hope is squandered.
But he is such a pivotal figure in British politics, it is almost impossible not to ask him why he is doing this.
His answer, in part, is because of the missionaries that used to come to his father's church. Ever since, he says, Africa has been important to him.
I've absolutely no doubt whatsoever this is heartfelt.
But he also believes it is time for the world to see a new Gordon Brown.
Not the dull, reassuring bank manager but a man driven by a moral passion - and it just so happens the Labour Party feels an awful lot happier ridding the world of debt than ridding the world of dictators.
There's also a sense of liberation. If Mr Blair won't allow him to run the election campaign then he can at least pretend it was all getting tedious and he'd much rather be out examining social problems in the raw.
It also goes some way to solving one of the overarching problems for all politicians of all parties: scepticism sliding into cynicism about politics itself.
If he can help the world's poor just a little, then it shows politics isn't worthless.
But is his vision for Africa too grand? Can poverty in the continent really be halved?
Brown replies that no one thought the Berlin Wall would ever come down either.
He's still got to overcome not only the reluctance of other finance ministers in the world - but also the cynicism of experts who wonder whether debt relief will just be squandered by governments that just won't in the end spend wisely.
Cape Town, South Africa: 1500
The last visit of the tour sees us visiting the township of Langa, fighting our way through the debris of a fire that has left 12,000 homeless.
It only happened on Saturday. Charred mattresses and discarded clothes lie among the ashes. The corrugated roofs now on the ground become makeshift bridges across puddles left by the fire-fighters.
Chicken and goats snuffle among the charred mattresses and tyres. Only the brick built buildings which used to be hostels in the days of apartheid remain standing; the wooden shacks of course burnt to the ground.
One family tells Mr Brown there were three beds in the room in the house they were in - that's not one family in a room, that's one family in a bed.
The chancellor talks to a woman who makes £100 a month selling snacks of barbecued sheep's intestines.
He asks the interpreter earnestly, does she have trouble obtaining micro credit for her inventory?
The interpreter looks frightened - it's Brown at his best and his worst. The question is actually bang-on - the problem is buying enough stuff for the next day. But he can build a wall of incomprehension with his intellect. Such lapses have become a bit rarer on this tour.
Cape Town, South Africa : 0800
The Mandela home is a large affair - a Marbella-style villa which would do any footballer's wife proud. While we are waiting for the meeting to end, the security police try to teach me the clicking sound which is a feature of the Xhosa language.
Later a colleague tells me a story of a BBC correspondent who practiced and practiced the sound only to be told after filing his report: "There's some weird clicking sound on your report - could you file again?"
There's bad news for politically correct fans of Mandela. The large hallway into his house is dominated by a lion skin and leopard skin rug complete with snarling heads.
Brown and Mandela laugh and joke as they say goodbye - it seems they really are good friends. Mandela rang Gordon Brown the day his son was born to congratulate him.
I think one of the things people like about Mandela is his self-effacement. At the end of our impromptu interview he talks about not being stigmatised for having TB in the context of Aids today, and adds "except to say that the old man is old and can pass away now."
My cameraman and I briefly abandon BBC objectivity to shake the great man's hand. On the plane back I interview Brown and chat to him.
He is the most relaxed I've ever seen him. He says he thinks what he calls the "personality issue" back home doesn't seem so important after this trip.
But this is surely as much strategy as sentiment. He's clearly decided he's got to shed his rather boring image - which he justifies as a necessary way of reassuring the public about the economy - and return to the basics of campaigning on really big issues.
Someone recently warned the chancellor that the public has moved from scepticism about politics to cynicism. He wants to persuade people that it can make a difference for good.
And if the public think he's less boring in the process, he won't mind.
What in Westminster is known as the TBGBs (TonyBlairGordonBrown) is about ambition, but it's the personal relationships which make it so charged.
It's not so much the chairman and chief executive of a business wrangling about strategy, but two brothers arguing about who mum would really have wanted to have her engagement ring.
I asked Brown if he'd been hurt by what had happened recently: "No, I get on with my job as much as I can."
He added that he at least is going to travel the country, listen and not lecture and not give the usual political answers.
"You should get out more" has become an all-purpose put-down, but it's true of all of us on this tour, both hacks and Treasury people.
On our last night in Africa, we are all in a reflective mood. This has been hard work - 18 hour days and relentless travel, but the feeling is like that at the end of a good holiday - the dread of going back to the humdrum and familiar.
We reflect on the wisdom of newsdesks finding the defection of a Tory MP more important than Mandela's thoughts on Aids. Damn, gone native.
Johannesburg, South Africa : 1200
In a light aircraft on his way to a private meeting with Nelson Mandela, Gordon Brown is excited to be visiting South Africa's former president at his home near to where he was brought up in the former Transkei.
Even though the chancellor has met the Nobel Peace Prize winner a number of times, he says that Mr Mandela has always been kind to him and telephoned him on the day his son John was born in November 2003.
More importantly he has done some diplomatic arm twisting, urging world leaders to back Gordon Brown's plan for Africa.
At Nelson Mandela's house, surrounded by lush gardens which were designed by the BBC One's Ground Force programme team, the press corps drink orange squash in the hallway to the grand villa.
My cameraman, Tony Fanshawe, asks one of Mr Mandela's security guards where we can film me so I can be in the sun.
He takes one look at my lobstery face and says I have probably been in the sun enough.
Maputo, Mozambique : 1100
In Mozambique, there are well preserved war graves at Pemba and Beira. In fact, World War I lasted longer here, I am told, than anywhere else.
The Germans fought on until February 1919 under a determined guerrilla leader. Gordon Brown has been talking about Remembrance Day as an enduring British value.
He says that Britain should stop apologising for colonialism and be proud of its history. While missionaries went to Africa out of a sense of duty, African soldiers died to defend British values of liberty, tolerance and civic virtue.
Mr Brown is continually portrayed as a bit of a leftie compared to the prime minister.
And this is a chance to burnish his credentials with newspapers like the Daily Mail.
I suspect if prodded he might not quite defend the Empire - but just argue that it's an old argument best forgotten.
And those missionaries did act out of a sense of duty, didn't they? It doesn't mean they were right or wrong. Even so, it is a fascinating question - when one stops making moral judgements about the historical past?
We learned this week that the Africa Corps is well beyond the pale. My advice to any young royals is go to fancy dress parties dressed as a British district commissioner next time - and you'll get the chancellor's backing at least.
In private, Gordon Brown has been seized by a new theory, based on his observations here in Africa.
It's that it'll be women who really transform this continent.
And after his trip, he's even more impressed with Africa's women.
A first experience was meeting members of a women's credit union.
They told him they have to work because they can't trust their husbands to come home with the money. And he's impressed that young women were willing to talk openly in front of thousands of people about being forced into prostitution by economic circumstances.
He waxes lyrical that all the people he's met who are taking real local initiatives are women.
And now he's met up with Luisa Diogo, his opposite number in Mozambique - their finance minister.
Well, not quite his opposite number. She manages to combine the job with being prime minister.
Before he gets ideas, we think there is a story.
Ms Diogo has made a speech, aides admit, that embarrassed the chancellor.
Why ? What did she say ? Because it was so full of praise for him.
Dar es Salaam, Tanzania : 1650
Gordon Brown finds it notoriously difficult talking about his personal life and his emotions.
Of course, throughout this trip we have been interested in what he feels when he sees the sort of poverty and suffering that he has come here to witness.
He has told us that in the last day or two he has seen "Grinding, abject relentless poverty and glimpsed the aching souls of millions", but has also seen, "The hopes in the eyes of young people".
But sometimes when he talks to those young people he can seem stiff and formal, asking seven-year-olds, "How do you do?"
Dar es Salaam, Tanzania: 1500
As I sit in a comfortable chair in a balmy Tanzanian night, broadcasting by satellite phone looking out to a vista of palm trees, I realise that years ago this was what I imagined journalism would be like.
Quite how I got side-tracked into spending most of my evenings trapped in that rain-swept wind tunnel called Downing Street, beats me.
But our TV pieces are filed from what is called a ground station.
If you're ever in 'Dar', as old Africa hands call it, you head out of town, turn right by the bright red shop called 'Rene's ladies fashion' and then endure the potholes for about half a mile.
Then you smile at the uniformed man on the gate, just by the sign 'Keep Out! Entrance Strictly Forbidden'.
Keep on driving for a bit and you'll pass a massive satellite dish in the middle of what seems to be a field.
Just a bit further on, amid a few trees, are a number of grubby single-story buildings. But when you're in the right one, there are banks of buzzing electronic equipment and TV screens.
It's the sort of place you expect to be stormed any minute by James Bond dealing with the baddies.
As we leave I look nervously around for signs of Thunderbird Two taking off
from the ground.
Dar es Salaam, Tanzania : 0930
On this visit we are all lobby correspondents so we have to explore the dynamics of the relationships at the top of British politics, or, in other words, try to get a cheap headline out of the chancellor.
Mr Brown said he has glimpsed the aching soul of millions.
So we asked Mr Brown could he see a future acting on the world stage?
"Oh junket Brown" he says," I can see the headlines now".
But he has missed the point. We're trying to chase the suggestion of Blairites that he should be shifted to the Foreign Office.
So I try again. Another job might give him the opportunity to do more about the state of Africa?
"Junior trade minister?," he asks.
No result there, then.
Dar es Salaam, Tanzania : 0900
I've worked for Newsnight. I've worked for the Six O'clock and the Ten O'clock news.
People on the tube occasionally ask me if I've got a scruffy brother who is on TV.
But only now do I feel the hand of fame tugging at my trouser leg.
The local Guardian newspaper here has printed this very diary, dominating page ten, under the headline: Goat Stops Chewing and Looks Up.
The managing editor should expect a big fat invoice.
Dar es Salaam, Tanzania : 1815
The Chancellor is settling into this trip.
Some visits are private, some rooms too small to contain the entourage of journalists, civil servants and local dignitaries.
So Gordon Brown emerges to report with increasing enthusiasm what he has seen and done. There is an air that he is relishing getting out from behind his treasury desk, and if ever Dar es Salaam South needs a new member for parliament...
But the bulk of the day is spent talking about AIDS. It's hard to avoid sounding mawkishly sentimental reporting even the conversations.
The Chancellor crams into a tiny two-room mud hut to hear one dying man tell him that he was too poor to travel to see his doctor, too poor to eat properly.
He added that his neighbours hated him, but he believed that all men were brothers.
The Chancellor touched the man's wrist and said indeed they were.
I was rather glad that when I asked Mr Brown about his feelings, he muttered "Very moving", and failed entirely to come up with a glib sound-bite.
I'm beginning to know what it must be like to be a spending minister in this government, and trying to understand the details of debt relief. Gordon Brown is briefing us in the back of Tanzania's Airforce Two.
You think you've grasped the concept when suddenly it veers away and gets completely lost.
Trying not to be impatient, Mr Brown explains that what you thought was borrowing turns out to be spending so it doesn't add to Britain's own debt.
I never realised the connection between economics and quantum physics before.
There is a childish glee among us all in the press corps when at one point he turns out to have been muddling dollars and pounds.
By the way, I misled you earlier. The topaz porcelain bowls on the plane looked pretty much like plastic on closer inspection, as do the samosas, the snack of choice on Tanzania's Air force Two.
Dar es Salaam, Tanzania : 1130
A convoy of minibuses drives through the countryside to the little village of Chahwa. People stop working in the fields to lean on their hoes and watch this strange procession.
A little girl playing in an old truck tyre waves and when we wave back ducks back inside the tyre. Even a goat stops chewing and looks up at the progression of the chancellor.
Mr Brown is in Chahwa to see for himself the new school - a sturdy construction of concrete and wood among the low huts of baked brick which are just a slightly darker colour than the bare red earth surrounding them.
The point is the school can be built and education can be free here directly because of debt relief: Tanzania has promised if it's let off its debt by Britain it will spend it on education.
Aid is a hugely complex subject and journalists by nature look for flaws in an argument but I must admit I'm stumped today looking for an interviewee who'll tell me this is a dreadful idea.
As we walk down the long ribbon that is this village, the chancellor, in slow translation, is receiving an education in African vegetables.
Mr Brown is a rumpled Pied Piper surrounded by children bearing mattocks rather taller than themselves in clean but frayed white shirts, the girls in brilliant indigo skirts.
The kids are so cute we suspect the Treasury of hiring them. Mr Brown asked the children "Who wants to be a doctor? Who wants to be an engineer?"
I try my luck and shout out "Who wants to be prime minister?"
But Gordon's too smart to allow his hand to shoot up.
Dar es Salaam, Tanzania : 0750
We are flying through the rural centre of Tanzania on the country's version of Air Force 2 - the president has loaned the chancellor his second aircraft.
It's the first plane I've been on, though one bulkhead has been replaced by intricate and rather gorgeous African wooden carvings of people at work and play.
The doors separating the VIP areas from the cockpit has a painting in pastel shades of Mount Kilamanjaro, shrouded in mist.
But our safety has not been put at risk by these nicer touches: the topaz porcelain bowls of roses are carefully stored away before we take off.
Dar es Salaam, Tanzania : 0500
One of the problems with these trips is that at some time you actually have to peel off and start editing the material that you have garnered for the radio and TV bulletins.
That means that we missed what his aides say was Gordon Brown's best visit so far of the whole trip.
He went to a town just outside Dar es Salaam, in Tanzania, where both civil servants who witnessed the event say he was virtually mobbed by the crowd.
Not so lucky the local politician who stood next to him with a fixed grin while the people demanded a new bridge to their town.
The highlight of Thursday's trip is, according to the local Guardian newspaper, a visitation to a modern slaughterhouse. I can hardly wait.
In fact Thursday's visits are organised around the theme of HIV/Aids.
The chancellor has made a big speech on the issue, saying that it is not a crisis but a daily emergency leaving 11 million children in sub-Saharan Africa without a parent.
He told business leaders and politicians in Dar es Salaam that Aids had made Africa poorer than it was before by discouraging primary education, killing teachers, increasing malnutrition because of the difficulty of gathering food and damaging investment.
Part of his vision for Africa is that he wants another $10bn a year spent fighting the disease and proposes research into an Aids vaccine similar to that on the human genome, where it is made one of the world's top scientific priorities with information shared widely, rapidly and above all freely.
Nairobi, Kenya : 1240
We decided it'd be good television to do an interview with the chancellor surrounded by a mass of good-humoured humanity. So we walked along the shanty town's main street which is lined with shacks hammered together with bits of old wood and rusty metal.
The shacks are selling batteries, eggs and plastic plates. Goats rummage among the rubbish.
But the walking interview is brought to a standstill as dozens of radio microphones from local stations are thrust in our faces.
Surreptitious shoving from my producer's elbow shifts no-one, but it does mean my story is the lead on the lunchtime news here. Then on to the tree-planting ceremony with the latest winner of the Nobel Peace Prize, Wangari Maathai.
She urges commitment to peace, the environment and good government, from both politicians and citizens.
It's what she calls a three-legged stool.
Perhaps it's this very three-legged stool a senior civil servant clutches awkwardly by one leg as we continue our journey to Tanzania. But no, the very small wooden seat is a gift which cannot either be packed or discarded.
The chancellor is tickled by a sign he sees on the way to the airport. It says "The government urges you all to pay your taxes and introduce freedom."
He noted it down on the back of a speech so it may yet appear in the manifesto - if the chancellor gets to approve anything in the next manifesto.
Nairobi, Kenya : 1015
Even in the heart of Africa's largest shanty town, Kibera, home to half a million people, the Chancellor Gordon Brown can't escape it. I asked one local, Ernest Osairi, whether he knew who the visiting dignitary was.
He did. "He's Tony Blair's biggest rival", he said.
A smiling, shirt-sleeved Mr Brown has just been to the Olympic school in Kibera where girls dressed in pale blue have performed a catchy number, ending in the chant: "Free education" with fists raised aloft.
They literally sing the praises of the Kenyan government for introducing free education.
But Mr Brown's message is that the goal of primary education for African children is further away than ever and he's asking the richest nations of the world to stump up another £50bn to deal with this and other problems of poverty.
I asked Mr Brown afterwards about the sing-song. He said he has no plans to introduce it into British schools.
Nairobi, Kenya : 0730
It's a widely held view at Westminster that Gordon doesn't do abroad. He travels for meetings but he tends to dart in and out.
The last time he went to Africa was seven years ago, when he spent twenty-four hours in Johannesburg. So why make a week-long visit to the continent, taking in the biggest shanty town in Kenya, an HIV AIDS orphanage in Tanzania, and a women's credit union in Mozambique?
In part it's to highlight the British government's intention to make tackling poverty in Africa their central task as this year's chair of the G8 - the group of the world's richest countries.
Stunningly enough, he and they actually believe in it.
In Mr Brown's recent announcement of a full-scale aid plan for Africa, which he compares to the United States Marshall Plan which rebuilt Europe after the Second World War, he talked of being part of a shared moral universe.
And it just so happens that we all expect a British general election this year, and for the government as a whole, this focus on Africa has distinct advantages.
When it comes to foreign policy, any distraction from Iraq is welcome.
And then there's the raw, personal politics. The recent tensions between Tony Blair and Gordon Brown have all been about Mr Brown's conviction that he should be prime minister by now.
He isn't, but he can do what prime ministers do: look concerned in shirt sleeves as cameras follow him around picturesque places revealing a more rounded person than the gruff finance minister usually displays.
Abroad has its advantages.