I am waiting to meet former CIA spy Melissa Boyle Mahle at a French brasserie in Washington DC. As people walk in and out of the café, I suddenly realise that I have no idea what she will actually look like.
I have read that she uses a number of different disguises – wigs and spectacles, even latex masks that transform her face. On occasion she has dressed as a man.
So I scrutinise everyone – first an elderly fat woman, then a tall African-American man, even a child. Surely she couldn't pull that one off? When she does arrive – 20 minutes late – she is, disappointingly, unmistakable.
Tall with cropped blonde hair and piercing blue eyes, she is brisk and businesslike. 'Melissa Boyle Mahle,' she says, extending her hand. 'And that is my real name.'
We go to a secluded dark table at the back of the restaurant. She chooses a chair with its back to the room near an emergency exit, so no one except me can see her face.
Old habits, it seems, die hard. For Mahle – who spent 14 years undercover – is a spy no longer.
Ousted from the organisation, due to an 'operational mistake', she now works as a foreign policy adviser (she won't say to whom), and recently acted as a consultant on the forthcoming spy film Salt, which stars Angelina Jolie as the CIA agent Evelyn Salt.
Jolie's role is based, loosely, on the experiences of Mahle and other spies.
'I was very impressed when I met Angelina,' says Mahle. 'She was very intent upon understanding not only what a real CIA officer was like but also the motivations behind our actions.
She wanted to know exactly what I would or wouldn't know and do.'
In the film Jolie is actually a Russian spy who has infiltrated the CIA. 'Which I obviously wasn't!' says Mahle, who worked mostly in the Middle East.
'She has a secret identity beyond all of that. But as an intelligence officer that's what I did my whole career – I took on secret identities, I lived that on a daily basis.'
She worked on making the script more authentic. 'Initially, it was not very realistic. The big concepts were good: the idea of Russian sleeper agents is very real, as we find out again…'
She is referring to the recent news of the Russian spy ring in America – fortuitous timing for the release of the film. 'I'm impressed by the power of Hollywood to arrange this,' jokes Mahle.
'It shows how real the Salt story is, in that you could have somebody – like Anna Chapman or whoever she really is – come to the US and integrate completely into our society.
Chapman looked like a New Yorker, acted like a New Yorker, she blended very well into her environment – obviously not well enough, as the FBI was able to get a thread.
But I'm chuckling at people's shock that, "Gee, the Russians are spying on us." Of course the Russians are spying on us and of course we're spying on the Russians!'
Salt captures the breathtakingly dangerous life of the secret-service agent: shoot-outs, car chases, death lurking around every corner. Was Mahle's life really like that?
'I was scared a lot of times,' she admits. 'Just because you don't get caught doesn't mean they're not watching you. Sometimes things can move in ways that are very dangerous for you. It's a survival game.'
Did she ever think it was just not worth it? She shakes her head: 'You have an objective, you have a mission to accomplish and you want to make sure you accomplish that mission.'
In one scene Jolie is peeling off a latex face mask. 'I can't reveal whether I used face masks,' says Mahle. 'But I did use disguise a lot. It could be small things – just wearing a pair of eyeglasses to change the shape of your face.
Or it could be more transformative – wearing wigs, changing into local clothing, transforming your face so no one could recognise you. Stuff out of Hollywood.
Actually the CIA learnt a lot from Hollywood; they were schooled by experts in make-up. And often I would pose as a man, if I wanted to move through a situation.'
Today there is no mistaking that she is a woman. Her face is carefully made up and she wears dangly crystal earrings and an eggshell-blue trouser suit with white sandals.
She is in her late forties, although she does not want to reveal her exact age. 'I won't even tell my daughter [who is 11], although she is quite persistent and keeps asking.'
Being a woman, she says, was the least of her problems. 'As a woman I'm not threatening. I could actually use it to my advantage.
Obviously, one of the first things you've got to lay down is, "This is a professional relationship. I'm not going to be your girlfriend so don't even think about it."
People think that is more difficult in the Arab world, but actually I had more difficulty with Europeans – with Frenchmen in particular!'
Her job, essentially, was to build relationships with possible informants. 'It's a highly manipulative skill. You are getting people to do an unnatural act – to betray their country.
And it all depends on how you interact with people. But I never did anything I couldn't sleep with, and I always believed what I did was to the betterment and the interests of the US government.'
Mahle spent most of her 14 years as a spy in the Persian Gulf, the Occupied Territories and North Africa. Shortly before her first mission she married Dick Mahle, her long-term boyfriend from California, in a secret wedding due to the CIA's security clearance process for spouses.
The 'real' wedding took place three months later, her guests unaware that the couple had already married. No one apart from her husband knew about her job.
The CIA manufactured a fake job for Mahle, which she used to deceive everyone, even her parents. 'I can't talk about my cover, even now.
My mother would worry about the places I was being sent and would say, "Why do you want to go? It's dangerous." My response was always, "It's an adventure!"
I lived my cover closely; you tell so many lies over a whole long period that I now can't remember exactly what I told them.'
Growing up in Carmichael, California, she hoped to become a music teacher. She studied music at Berkeley, where her professor told her she was not good enough to make it.
'At that time the King Tut exhibit came to San Francisco. I'm embarrassed to admit this because it sounds so unprofessional, but I became fascinated by Egypt and I wanted to know why I didn't know anything about it.
I ended up studying archaeology and becoming an Egyptologist, and that was really my pathway to the languages and cultures of the Middle East. I just had no idea that the path would take me to the front door of the CIA. So you could say I was an accidental spy.'
Another professor, who may or may not have had CIA links, suggested her studies might make her interesting to the organisation. 'I had never thought about a career in intelligence, but somebody spotted me and assessed I had exactly the skills that might interest them.'
Dick accompanied her abroad but knew little about the details of her job. 'He retired from his career [as an industrial salesman] when we went overseas.
Sometimes he worked if it was permissible, otherwise he played a lot of tennis and taught himself to use computers. He knew very little about what I did, and it was an understanding from early on that he did not ask questions.
I only provided information when I felt it was appropriate, and I would say on a scale of 1 to 10 with '1' knowing nothing and '10' knowing everything, he was probably at one and a half.
'It takes a lot of trust in a relationship to be able to handle that kind of lack of knowledge. Think about this – I would get up and go out in the middle of the night and what would I be doing? There was no way to contact me.
He's a remarkable man and he dealt with it very well. Working as a spy can be a real marriage-buster.'
After 10 years as a spy, Mahle gave birth to a daughter, Hana, in Jerusalem in 1998. Between contractions, Mahle debriefed the secret service.
'President Clinton was coming out for a historic visit. His security was obviously extremely important; to lose a president is very bad for your career! It was also the precise moment when Saddam Hussein was threatening a chemical attack against Israel.
'I was also an accidental mother – although a very pleased one – but I didn't really have time to deal with being pregnant, and I certainly didn't have time to deal with the realisation that my baby had decided to come early. I have to say at the beginning I thought motherhood was an issue of time management, but I learnt very quickly that was not so.'
Stuck for a baby-sitter on occasion, she even took her baby daughter to meet Yasser Arafat. 'She came with me several times. When you get a call with a request for a meeting, there is no time to go home and farm the baby off.'
As a mother she found the inherent danger in her job less tolerable. 'There were a couple of moments that terrified me after the fact. They were enough to make me think that I needed to make some choices about my career and being a parent.
No disrespect to my husband, but I never felt that with him. It's very different when you have a child to protect.'
Nevertheless, she did not consider leaving the agency, just changing her set-up so that her daughter stayed in America and she worked overseas. In the end it was solved for her when the CIA 'retired' her in 2002.
She cannot go into specifics. 'Ring me in 20 years and we'll talk,' she says. 'Frankly, I did not like the process that led to my departure from the CIA, but I look back now and I say, "If you don't want me, you don't deserve me.'
At the time, however, she felt bereft. 'It was unbelievably difficult. You become an adrenalin junkie – not only do you suddenly not know the inside stories of world events, but it was very difficult to get used to the phone not ringing, to not hearing that the president has read your comments on a subject.
What do you do after being a spy? Do you sell insurance? And how do you get a new career when your resumé is blank?'
It was difficult on a personal front, too. So successful had she been at hiding her identity that she even managed to disguise it from herself.
'You have spent your whole career shifting skin to become whoever you need to be and suddenly you have to be you. And who is "you"? I didn't even have opinions on anything.
It would drive my husband crazy; he would want to know where I stood on something, and my personality was so suppressed I didn't know.'
She had to train herself to tell the truth. 'When you live a life of deception you get to be very good at it; a well-constructed lie is a lot more useful than the truth.
I had to grapple with making the truth the first response. Even at home it is problematic. I caught myself saying to my daughter the other day, "I'm sorry sweetie, but McDonald's isn't open on Tuesdays."
It worked for the moment; I was crafting a story that would get me what I wanted. But it's not exactly setting the sort of role model that you want for your children!'
Along the way she lost a lot of friends. 'I have friends who will never forgive me for deceiving them. Luckily, I also have friends who think it's so cool they'll forgive me no matter what…'
Her parents understood. 'I'm actually very close to my mother, so it was hard to hide it from her. When I left the CIA and told her she looked at me like "Oh my gosh." She had never suspected. As for my father, he was suitably excited and intrigued.'
She finds she still craves excitement, and after leaving the agency set herself different goals. She travels to offbeat places like Bosnia with her father – 'I get my adventurous streak from him.' She also climbed Mount Kilimanjaro. 'I climbed it as an act of clarity, hoping to see my future,' she says, laughing.
'And I get to the top and it's a blizzard. It's like a reaffirmation of the world of intelligence. There is no one there. You never arrive.'