In the baking heat of a Gulf capital, a chilly but historic meeting will begin to end a war.
American negotiators will sit down with black turbaned men from the Taliban, at least one of whom speaks impeccable English.
I last met Tayeb Agha when I was embedded with the Taliban in 2001 in one of their last strongholds and he was the special envoy of the Taliban leader Mullah Omar.
They will set out their vision of what peace might mean, at the end of a war that has already lasted longer than any war in American history and has cost nearly two and a quarter thousand American lives. Taliban losses are undocumented but they are many times that of their enemy.
It is a groundbreaking moment, yet peace is not about to break out.
At this first meeting both sides will set out their agendas; the issues they want to address. The Taliban announced five key points at a news conference they gave in the same office on Tuesday, an office they see as the foundation for a diplomatic outreach to the world.
The Americans will set out their proposals which will include an acceptance by the Taliban that they will keep a garrison of several thousand troops in the country to guard against it being used ever again by groups who plot to attack the United States.
The agendas will be very different.
But they have one mutual area of interest; prisoners. The Taliban want five of their men released from detention without trial in Guantanamo Bay in Cuba. The Americans want the Taliban to release the only American prisoner of war, Sergeant Bowe Bergdahl, who was captured four years ago after wandering off base in the east of the country.
This prisoner swap was mooted last year as a "confidence building measure" between the two sides. But the Americans were, in the end, reluctant to release men from Guantanamo in the midst of a Presidential election campaign. It would have made Obama look weak. The Taliban accused the Americans of duplicity.
After the meeting, the real discussions will begin, between Afghans. Or at least that was the plan. But in peace, as in war, sometimes the first casualty is the plan.
President Hamid Karzai, furious that the Taliban appeared to present themselves as a shadow government in exile, negotiating with America in a foreign country, yesterday called off his talks with the Taliban. He refused to take part until the discussions were led by Afghans.
Karzai is a deeply proud man. He felt his office and his administration were being stepped over by both his enemies and his allies, the Americans. This won't last. He has thrown his toys out of the pram, but he will pick them up in time and send his High Peace Council to talk to the men in black.
But the stakes are high. The Taliban regard Karzai as a puppet. They want to see him dead. As the Taliban talked peace in their new office, their comrades were trying to kill a High Peace Council member with a suicide bomb. They failed.
The talks will be, as President Obama has acknowledged, complex, long and messy.
But they are the start of a long road out from a long war. America's battles in Iraq and Afghanistan will end when their only prisoner from those wars, Sergeant Bergdahl walks free. Until then, the killing and the talking will go on in lock step.