She also rhapsodises about the retail opportunities offered by espionage work. 'Sometimes when I'm out following a target who's gone shopping, I get to go shopping too,' she explains.

'Or sometimes, as I'm passing through an area following a target, I might see something in a shop that I like and think to myself, hmmm ... I'll have to go back there.'

Foiling terrorist plots or foreign agents bent on doing Australia harm is little different from her old life as a girl-about-town, Alison insists. 'As for dating, it's not like anything has really changed. Even before I joined ASIO, I would go out to pubs and bars with my girlfriends and, for a laugh, we'd sometimes all pretend to have different names and identities.' But Alison warns that it's not all lattes and laughter: she is unable to tell her family what she does for a living.

'Whenever someone asks me what I do, I have to make up a story to tell them.'

Overall, though, she has embraced the dark arts of espionage with schoolgirl enthusiasm: 'It's like I live another person's life every day!' While Alison's affidavit has the vacuous chirpiness of a female character from The Spy Who Shagged Me, a male colleague reveals a hard-bitten streak more reminiscent of a John Le Carre thriller.

The strain of spying has taken a toll on the family life of 'Andrew', a 40-year-old career spy who admits that staking out a target in a car for hours on end can be numbingly dull.

'But there were also periods of unbelievable excitement and adrenaline,' he said. 'I wouldn't have given that up for anything.'

ASIO has almost doubled its staff, to more than 1,000, since the September 11, 2001, attacks on the United States. But amid fears that Australia's involvement in Iraq and Afghanistan has made it more of a terrorist target, there are now plans to double the workforce again, recruiting 250 new agents a year over the next four years. The case studies will appear in publicity material in coming months.

No doubt Osama bin Laden will be quaking in his mountain hideout.