The war in the Democratic Republic of Congo has been the most faceless of conflicts. The unbearable statistics threaten to fade into abstraction: an estimated four million people killed, tens of thousands of women raped, countless numbers displaced and lives destroyed.
But last week the bloodiest and least reported horror story of our times took on the indelible features of a single face.
At 46, Eraste Rwatangabo looked far younger. He lived on the high plateau of South Kivu in the far east of the Democratic Republic of Congo (DRC). No one who has been to that stark corner of the world forgets its atmosphere.
It rises out of the dense jungle that flanks it on all sides. Every morning a thick mist hangs over the plateau, which stretches, gently undulating, for hundreds of miles. And almost every morning, for more years than anyone can care to count, out of that soundless mist have come new stories of displacement and terror.
The high plateau, rich in mineral resources, including gold, has been a battleground in a conflict that over nearly two decades has drawn in six countries; it has suffered both the brutal fallout of the genocide in neighbouring Rwanda and the chaotic ethnic and factional war in which the lawless Congolese army has been only one of many actors.
It is a few hundred miles upstream from the setting for Conrad's Heart of Darkness. The people here, mainly the pastoralist Banyamulenge, have known little but relentless hardship and sporadic violence.
Rwatangabo immediately stood out. Educated to degree level in history and articulate in several languages, he carried the idea of a different future for this plateau in his easy stride and broad smile. The local people called him "captain", but his mission had never been a military one.
Rwatangabo was a fighter for hope and education in a place where there was precious little of either.
He had grown up in South Kivu, married in 1982, and had eight children, two of whom had died. After completing his degree in Rwanda he returned to the high plateau to teach and became a schools inspector before working for the Red Cross.
In 2006, during the country's first national elections, he was the president of the election commission for the region, travelling between villages explaining to people why they must vote.
Since then, in the most desperate corner of the most ungovernable country on Earth, he had been responsible for wielding perhaps the most powerful of all weapons for change: a teacher training programme. This was no ordinary course of study.
Established by the Reverend Samson Muvunyi, from a Christian mission called Eben-Ezer Ministries (EMI), it had grown out of a peace and reconciliation movement that sought to include all the factions divided by war; to give children a textbook rather than a machete to carry; to build a fresh start.
In 2008, I had flown to South Kivu to report on an emblematic story of that fresh start. Ron and Pauline Friend, from Orpington, Kent, in south-east England, had sponsored a school in memory of their son, who had been caught up in the conflict in 1999 while travelling on a gap year.
Martin Friend had been murdered by former Interahamwe genocidaires from Rwanda, and Ron and Pauline were travelling to the high plateau to open the school that they had raised the money to pay for in their son's name.
The school had been built in a place, Mishashu, where there had previously been not a stick of chalk. It was constructed by the women of the village, who had hauled stone and cement and water up miles from the road. At its opening, the 300 children who would study at the school couldn't stop wondering at the marvel of desks and whitewashed walls.
The more time we spent on the high plateau, though, the more we realised that Ron and Pauline's school wasn't an isolated miracle, but part of a growing network.
That network was being established and strengthened by the British charity Children in Crisis in partnership with the EMI programme led by Muvunyi and Rwatangabo. A total of 192 schools over a vast area were included in this programme. Many had been burned or destroyed in the conflict. But nearly all, it seemed - with the efforts of EMI and Children in Crisis - were being restored as brick-built symbols of possibility. This was made possible in large part by Rwatangabo's energy in inspiring his team, even as the war in one form or another was still being waged.
Last week, however, the chaotic violence that Rwatangabo had been born into, and which he had done so much to fight against, finally caught up with him. On the long road through the jungle to the high plateau Rwatangabo was ambushed by a militia group and murdered at the side of the road, along with four colleagues and two of their relatives.
A leader of a theatre programme, Pastor Antoine Munyiginya, was also on board.
They were ambushed by a Mai Mai Yakatumba group. Mai Mai is the name given to any of the shifting and desperate gangs who get hold of some semi-automatic weapons and call themselves a rebel militia.
Yakatumba is the name of one of the more notorious local warlords.
The Mai Mai that attacked the Land Cruiser had, apparently, only one aim. They wanted to kill any Banyamulenge on board, members of the Tutsi-related ethnic group whom the "indigenous" Congolese Mai Mai consider incomers. Stopping the car, they ordered "the Rwandans" to get out of the vehicle. Two men and two women of different ethnicity who were travelling with Rwatangabo and his team were told to leave.
The account of what happened next comes from a man who spoke to Pastor Munyiginya, who survived the attack. The driver of the vehicle, Musore Ruturutsa, who had worked with Eben-Ezer for three years, was shot in the back. The others were taken a little way into the jungle. They were led by Munyiginya in songs and prayers. Each one, systematically - Rwatangabo; Kandoti Tite, his deputy education manager; Gifota Edmond, a newly recruited teacher trainer; Nabisage Rganza, 24, the sister of another colleague; and two others - was murdered in turn.
Eventually only Munyiginya was left. He was told to lie face down and the Mai Mai commander gave the order to "finish the job". A gun was put to his head, but he was shot in the hand. Antoine did not know why he was spared. Perhaps to tell the tale. He is in hospital with a bullet still lodged in his wrist and there is no doctor in the area capable of removing it.
The seven people murdered were buried two days later. In a place where any journey takes on the quality of an epic quest, 2,000 people attended the funeral at a day's notice.
Sarah Rowse, project director for Children in Crisis, was still struggling to comprehend the news.
"There are probably contexts in which you can try to understand it," she said, "but the thing about Eraste was that he always just seemed bulletproof."
President Joseph Kabila, whose family ties are in the Kivu area, has made the (extremely relative) stability of the region in recent years the main platform of his campaign. "No more fires in the east," he said "only embers". In this sense the murders could look like a premeditated effort to give the lie to that slogan.
It has been suggested that it was inconceivable the Mai Mai did not know the work of EMI, and who they were killing. He and Rwatangabo had spent years negotiating with various militias to explain their mission. As Rowse said, "Eraste worked tirelessly talking to commanders saying let these teachers travel in peace, [urging them] to not make the children carry munitions or weapons as they tended to do. People have listened to him. That's one of the reasons it just seems so unbelievable. Why it is a pure hate crime."
Despite their anger at the loss, Children in Crisis is determined that the education programme will continue. The immediate concern, they say, is to try to look after the families of those who were murdered and who have no means of support. A fund has been established. After that, the programme must find a way to continue. "Although Eraste's life has been cut short, and those of Tite and Musore and Edmond, what they have done can't be lost," Rowse said. "We must continue to believe that the foundations for peace are there in those schools and those teachers."
Region's troubled and bloody history
In 1994, after the genocidal Hutu government was overthrown in Rwanda, an estimated two million Hutus fled across the Congolese border into North and South Kivu in eastern Congo. They allied themselves with the government of President Mobutu Sese Seke and waged war on Congo's native Tutsi.
Backed by the governments of Rwanda and Uganda, the Congolese Tutsi fought back and, under the ruthless Laurent Kabila, Mobutu was overthrown.
When Kabila failed to destroy the Hutu, the Tutsi government of Rwanda sent a further force against him. Kabila called on the support of Zimbabwe, Angola and Namibia and for five years a proxy war was fought in the eastern Congo, driven by ethnicity and control of gold, diamonds and coltan, a key component of mobile phones.
The war officially ended in 2003, with four million casualties, and Kabila's son Joseph was elected in 2006 in the first democratic elections. Despite the presence of 17,000 UN peacekeepers in the east, the killing and mass rape continues, with those suspected of Rwandan loyalties targeted by ethnic Congolese gangs.
The Banyamulenge, a minority population of ethnic Tutsi Rwandans, are targeted as "foreigners" by Congolese militias, known as the Mai Mai.
How to help
To make a donation to support the families of those killed, go to childrenincrisis.org