Each shuffle of this diplomacy is accompanied by a cacophony of reporters' questions. "Can you make a deal?" often echoes loudest.
What we do know is that millions of people want this deal to work. They want to believe this world can be a safer place. They want to believe these politicians and scientists will deliver that. They want certainty and comfort.
Every page turn of history is written by moments such as this. Moments when men and women face their fears and step forward.
The sweltering heat on Tuesday felt like such a day. Vienna was on fire, 39 centigrade (102 Fahrenheit) on the streets. It felt like the Coburg's meeting rooms were the city's furnace, stoked by Monday's late night meetings. Pain and tension wrought in the heat of contentious debate.
That, at least, is how two top European diplomats vented their feelings.
But as the fires cooled, no words melded. There was no mixing of ideas in the Coburg's crucible. The mold was still empty. There was no agreement reached to withstand the verbal hammer blows of 1,000 critics comfy in their fireside chairs back home.
Sitting Wednesday in the rain, air rendered by thunder and illuminated by lightning, while listening to the drum beat of water droplets thumping off the fragile roof of the tent over our camera, I felt the momentum of the previous week's discussion dissolve.
Tuesday was surely a moment missed. A deadline come and gone yes, but it feels like much more. Was this the day history's page was meant to turn?
On Wednesday, there were no official meetings, no action, no talk, no deal. The hope of millions seemed utterly misspent -- invested in the wrong moment.
But then perhaps more hope of sorts. Federica Mogherini, the EU foreign policy chief who had talked of Monday's pain, met Iranian Foreign Minister Mohammad Javad Zarif. Rumors were already rife the two had had a falling out.
Next, we learned U.S. Energy Secretary Ernest Moniz, a world class nuclear physicist, met Iran's top nuclear man, the Iranian Atomic Energy Organizations chief Ali Akbar Salehi.
The weather was calming and the downpour easing, when from nowhere the brightest rainbow illuminated Vienna's fine Hapsburg architecture.
The arc of colors are always a metaphor for hope. The sun following the storm.
But a rainbow is circular when viewed from above -- not an arc but a continuous closed loop that is what these talks are in danger of becoming. The gold at the end as illusory as the silver tongued words that are needed now to finesse and filigree this deal. Words to bond the hopes of millions in to agreement.
Chances don't come often.
As we've been told this week by at least one official, history needs alignment. No it doesn't. It simply needs good strong people, on all sides.