In Geneva, one American and one Iranian try to rewrite history

Iran's Foreign Minister reacts to initial nuclear discussions 0:15

Our NBC News team was able Wednesday to speak to two major players in the Iran nuclear negotiations here in Geneva: Iran's Foreign Minister Javad Zarif and the U.S. Undersecretary of State Wendy Sherman.

Both signaled that what happened behind closed doors here was different from all of the talks that have come before.

We spoke to Foreign Minister Zarif just as he was leaving for the airport for a flight home to Iran. He was wheeled out in a wheelchair because of back pain, which he linked to the schedule he's been keeping in recent weeks working to present Iran's nuclear position. Before negotiators here, he used a PowerPoint and spoke in English, which was a first in the talks, allowing for greater clarity and pace in the negotiations.

We caught up with Undersecretary Sherman in her hotel on the eve of her journey back to Washington, still working hours after the negotiations had officially ended. Only the slight darkness under her eyes that comes with a lack of sleep gave away the stress she's been under.

Here is what we caught on camera:

U.S. Undersecretary of State says 'candor' and 'detail' in Iran nuclear talks 2:42

While it seems clear the nuclear talks with Iran are now jump started, it is also still clear there are enormous hurdles to their success. Based on what all parties are saying, it will be like threading a needle.