Just five months after BBC's Persian TV service went on air came the disputed June presidential elections in Iran, followed by mass protests, violence, and a clampdown on foreign media.
Since then staff at the channel - many of them young Iranians who only came to the UK for its launch - have been working double shifts, trying to produce extra programming on a highly sensitive story even as information has become harder to obtain.
Often this has been done under the extra burden of worrying about friends and family in Iran.
"It's very emotional for all of us," says Rana Rahimpour, a 26-year-old reporter.
"It's your home, it's your streets, the people you grew up with, the places you played in."
Torrent of contributions
In the days that followed the 12 June election BBC Persian - broadcast in Farsi but already banned from working in Iran - was jammed, forcing the channel to use two new satellites to try to get round the blockage.
Agency footage almost dried up, meaning it has had to rely on material sent in by viewers, known as "user-generated content".
"The user-generated videos suddenly became the main way of reporting," says Sina Moutalebi, who turns round interactive material for the channel's programmes and news bulletins.
The material has required careful sifting, including checking pictures taken of the same event from different angles against each other.
But the torrent of contributions and the story as a whole has clearly provided BBC Persian with a boost.
Though audience estimates are yet to be published, the channel - which had set a target of eight million viewers by 2011 - already thinks it has millions of viewers.
It increased broadcasting from the previous daily limit of eight hours, and streams BBC Persian radio when off air.
Up to 10,000 e-mails have been received on a single day, and there were some three million hits on the BBC Persian website on Saturday, the day of protests when at least 10 people died.
"For the past five to six months we encouraged people to send us user-generated video and to send us something other than from their tourist trips in Iran or to Europe," says Mr Moutalebi.
"Then suddenly they began to show us all this video from the clashes and demonstrations."
This has included not only passive, observational footage, but also actively gathered material such as an interview with a prominent critic of the regime conducted by a citizen on his mobile phone during a demonstration last week.
"The streams are getting narrower and narrower - from phone connections to internet connections, to people just being brave enough to contact us," says Pooneh Ghoddoosi, who presents the channel's interactive programme.
"It has become more and more sensitive and dangerous for people to talk to us or tell us their stories, but that has very much surprisingly not stopped them."
Even so, upholding BBC values of impartiality and balance has been a challenge.
Before the election, the interactive programme received a number of phone calls from people purporting to be opposition supporters, who began to sing President Mahmoud Ahmadinejad's praises as soon as they got on air.
Since Mr Ahmadinejad was declared to have won the election, his supporters have stopped calling, and Ms Ghoddoosi has been left appealing in vain for his backers to contribute.
Enayat Fani, who presents a political debate that was broadcast weekly before the elections and is now shown daily, says he finds himself playing devil's advocate with pro-opposition guests.
Contrary to the Iranian government's escalating accusations against foreign media, BBC Persian acting head Rob Beynon says the channel has reported the story impartially.
Staff have risen to the challenge as they concentrate on a big, complex story, putting their opinions, and concerns, aside, he says.
"We have been very careful about not falling into the trap of becoming opposition TV. We've at no point said 'these elections were rigged'. We've been very measured - so much so that we've had criticism from all sides."
Rana Rahimpour says no-one has yet heard of their families in Iran suffering any repercussions, though with some communications systems down or blocked, it is often hard to make contact by phone or e-mail.
"Anything is possible and I try not to think about it," she says.
"Although my parents fully support me in this I don't want to put them in any trouble or danger because of my decision."
Before the election some employees had booked trips back to Iran that they have subsequently had to cancel.
"Suddenly they realise it's dangerous for them to go back to Iran," says Mr Moutalebi, who was arrested by Iranian authorities for blogging in 2003 and spent 23 days in solitary confinement.
"They don't know when they can see their families, and then you have to come to work at 7 a.m. and be as objective as possible."