Iran nuclear: Drama in Vienna as talks go to the wire
"Drama is an important negotiating tool," a US official told a group of journalists last year in Washington before setting off for Geneva for talks with Iran on its nuclear programme.
Indeed, it was after a particularly blockbuster bout of diplomatic brinksmanship in the early hours of 24 November 2013 - when the talks appeared to be on the verge of total collapse before taking a sudden turn - that six world powers agreed an interim deal that saw Iran curb sensitive nuclear activities in return for relief from crippling sanctions.
A year later, there was a sense of history repeating itself for those covering the last round of negotiations on a long-term nuclear agreement ahead of Monday's deadline.
Journalists were scrambling to lift the tight lid on the talks maintained by both sides and struggling to weed through the disinformation, spin and rumours swirling around from various parties with interests in influencing the narrative.
"These are the hours of truth," German Foreign Minister Frank-Walter Steinmeier said before one of his meetings in Vienna with US Secretary of State John Kerry.
As the clock ticked towards the deadline, the mood in the lobby of the hotel in the Austrian capital where many of the delegates were staying vacillated.
On Friday, the space was buzzing and for the first time journalists were able to corner officials going to and coming from the negotiations.
But when the Iranian Foreign Minister, Mohammad Javad Zarif, cancelled his trip to Tehran for consultations at the last minute and Mr Kerry subsequently cancelled his departure to Paris, everyone thought something had to be up.
The next day, not a diplomat was to be seen and the mood became tense.
Mr Kerry spoke of serious gaps remaining between the two sides and was overheard saying, "We're stuck" and "We were ready to go".
Time appeared to stand still, but the negotiations continued like clockwork - meetings, calls to capitals, and more meetings.
Diplomacy in action, but with little divulged, is not what impatient journalists like.
Much like last year in Geneva, the Vienna hotel lobby was littered with reporters anxiously drinking far too much coffee and eating over-priced snacks to pass the time.
But this time it was far harder to get access to officials.
Tight security at the beautiful Palais Coburg, where the talks took place, meant it was virtually impossible to ask a diplomat in the lobby there for an update.
It even meant that whenever one of the foreign ministers arrived or left, anyone who happened to be milling around the palace's much smaller lobby would be trapped until the all clear was given.
With most ministers not renowned for their punctuality, and the journalists often knowing more than the head of security about their movements, the waits were often lengthy.
Inside the meeting rooms at the Palais Coburg, negotiating teams sought to bridge the gaps.
US officials revealed that the last round in Oman had been particularly contentious.
"There's no question that round was kind of a low point in the negotiations," one said.
The conversations between Mr Kerry and Mr Zarif even became heated at times, which was "unusual", the official added, before noting that the tone had changed in Vienna.
"Here, the meetings were less contentious and focused on substance rather than rhetoric and the gaps we were able to bridge shows effort on both sides."
One Iranian diplomat described the emotional toll of the talks.
"When you hit a roadblock, you feel it," the official said, describing the negotiations as a "rollercoaster" and how people on both sides comforted each other "del dary" - a Farsi term that can be loosely translated as "heart-to-heart".
One of the most dramatic moments of the talks was when news started to circulate on Friday morning that Iran's foreign minister was heading back to Tehran to brief the Supreme Leader, Ayatollah Ali Khamenei. Speculation mounted as to what it might mean.
When word got out that Mr Zarif was not likely to be going to Tehran anymore - but had an evening flight booked just in case - many assumed the worst.
US officials did not know the exact reason why he had decided not to go, telling journalists that "everybody has different tactics".
Mr Kerry decided to cancel his trip to Paris and stay in Vienna for a number of reasons, including having more one-on-one time with his Iranian counterpart.
"It is easier to get things done when others are out of town," one US official said, noting that even though Iran is negotiating with the so-called P5+1 - the five permanent members of the UN Security Council and Germany - the US is the other main player.
In fact, building a rapport with Mr Zarif was said to be key to Mr Kerry's negotiating style. "He really values those personal relationships," the official said, adding that it has taken quite an effort at times.
The US secretary of state is also believed to have made a concerted effort to learn the ins and outs of the nuclear issue, reading "binders of briefing materials.
Iranian diplomats compared their negotiating tactics to their nation's history. "Iran has stood the test of time - our style in the negotiations shows this."
Although the two sides failed to agree a deal before Monday's deadline, the talks have been extended until the end of June 2015.
As the details of the extension are worked out and a possible move to Oman for the meetings is debated, it appears for the first time that there is legitimate hope of success.
Meanwhile a senior US official told the BBC that they never really thought until the final day in Vienna that a comprehensive deal with Iran was actually possible.