As soon as the British Airways flight from London taxis to a stop at the Meherabad airport terminal, the women on board stand and reach into the overhead bins for their Islamically correct overclothes – a loose coverall called a "manteau," and a headscarf.
I have arranged for an Iranian colleague, Sia, to bring one of his wife's manteaus to the airport for me, but it suddenly dawns on me that I've miscalculated. Dressed for a London spring in light trousers and a bright T-shirt, I realize I have nothing to cover up with for the 200 yards through immigration and the baggage hall. I wonder, briefly, whether I'll be turned back before I've begun – shackled into my seat while the plane refuels and returns me to London for immodesty.
Then, my producer comes to the rescue with his raincoat – a short, sand-coloured, canvas model that makes me look like a 1950s cleaning lady, but gets me safely to the hotel.
That afternoon, shrouded in Sia's wife's black manteau, we set out for a press conference with Mahmoud Ahmadinejad, the democratically elected president of Iran. The room is crowded with journalists.
Many of them are women, dressed - like me - in dark manteaus and scarves. To a Western eye, these look severe and puritanical. It's an easy assumption that women who have given in to this oppressive code of dress have had their spirits and ambitions smothered too. But in Iran, a complex and fractured country, nothing is as it seems. These are as tough-minded and assertive a bunch of female reporters as you'd find in any American news conference.
The men from the Information Ministry make a list of journalists who have questions, then call us to the podium one by one. Since taking office, President Ahmadinejad has only twice faced the Iranian media, and has never taken questions from foreign reporters. Nevertheless, he handles the session with ease, and humour. The man who, a few months ago, horrified the world by saying, "Israel should be wiped off the face of the earth," does not come off as a wild-eyed fanatic.
"Is there anything the Western countries could offer Iran to persuade it to stop enriching uranium?" I ask when my turn comes.
After some sparring, Ahmadinejad finally answers, predictably: "No. Enriching uranium is Iran's legal right."
But the sharpest question came from a slim young woman, dressed in black from head to toe, who pushed her way to the microphone. Whereas my question focused on Iran's nuclear program, which is generally popular with people, she wanted to ask about Iran's limping economy, which is not. Unemployment is chronically high, and investment persistently low.
"Iran's Parliament doesn't like your economic policy ," said Farzanah Sayed. "And your performance falls short of your campaign promises. How do you explain that?"
For the first time, Ahmadinejad lost his bonhomie. "That's your opinion," he barked, and briskly moved on to the next question.
A few days later, we caught up with Farzanah Sayed in her small Tehran apartment. She works as a staff reporter for a business newspaper, but in her spare time writes a Weblog on an old desktop computer with dial-up connection. In it, she publishes everything that her editors don't or won't print in the paper.
This week, she has written that Iranian prostitutes and sex workers, who are denounced by the regime as immoral and degraded, are driven onto the streets in desperation. Corrupt bureaucrats and government officials, she writes, are to blame. They keep the poor powerless and impoverished.
For our interview, Sayed is wearing jeans, with a headscarf draped very loosely over her dark hair. Westerners are often offended that Iran's Ministry of Islamic Guidance insists that women here cover up in public. For Iranians, though, this is a minor thing compared to the curbs on freedom of speech.
"Did you hear my question at Ahmadinejad's press conference?" she asked proudly. "It wasn't authorized, you know."
Sayed explains that she didn't manage to get her name on the approved question list so she simply pushed her way to the podium and spoke up before anyone could stop her.
"Weren't you afraid you'd get pulled away by the Presidential bouncers?" I asked.
"No," she said smiling. "That's one good thing about this kind of Islam. Men aren't allowed to touch women in public."