Hastening out of Green Square into Souk al-Mushir street for a furtive meeting with a Libyan opponent of Muammar Gaddafi, you are confronted with a row of 10 identical models, the wax faces of sphinx-like young women dressed in a colourful array of headscarves from a nearby shop.
Maybe it's the abnormal times, or maybe it's the recently posted leaflets in the streets exhorting members of the public to report "destructive or suspicious elements", but today there seems to be something sinister about the models' display, like some leitmotiv from a Forties film noir – Carol Reed for example. Tripoli in 2011 is not remotely like the post-war Vienna of The Third Man. But it is irresistibly reminiscent of the world conjured by the film's original creator Graham Greene.
For we are surely in Greeneland. Perhaps only the author who indelibly brought to life Papa Doc's Haiti in The Comedians, or Batista's Cuba in Our Man in Havana, could do justice to the heavy atmosphere hanging over Tripoli in what may be the last weeks of Muammar Gaddafi's rule. The young men in the civilian militias Col Gaddafi is now boasting he has opened the national weapons stores to arm may not be exactly Duvalier's Tontons Macoutes, but the mixture of the picturesque and the faintly menacing in the Medina and along the Corniche is one he would have instantly recognised.
Amongst the rich cast of characters at his disposal, one of the less obviously colourful is the middle-aged man in his 50s we are going to meet in the old city; in fact, though, he is as caught up in this city's web of intrigue as any.
He was one of those who almost a month ago, when it seemed that Tripoli would rise up, was on the anti-Gaddafi demonstration which reached Green Square before it was repulsed. He talks in the argot of the European country he lived in for a decade. But he too is a patriotic Libyan. For someone with plenty of self-confidence he walks circumspectly towards us. Delete my phone number," he commands. "You can learn it by heart." The conversation is quiet, friendly and tantalisingly brief, ended when he feels that someone has walked once too often past our rendezvous point.
"The problem before was that no one trusted anybody. There might be three of you and you would be frightened one would tell; now there is just a little more trust [among active opponents of the regime]," he says. He thinks those on the missions to impose the no fly-zone have been doing a "good job" and that there is every chance that Gaddafi will fall; perhaps he will even commit suicide.
Some of his claims, and those of other opponents, are just as hard to verify as the regime's: that the young "volunteers" are paid to form the loyalist militias, that they are wired on drugs and alcohol, that bodies were brought from the fighting in Zawiyah to be used as evidence of civilian casualties from the bombing. But while he says that only 25 per cent really support him, there are those, particularly young people who have never known any other leader, who "think he's in their blood".
There are many devoted to perpetuating that impression, way beyond the pervasive presence of the Brother Leader himself, with his rambling denunciations of the "rats and vermin" teenage drug addicts suborned by al-Qa'ida, "colonialists" who, he is trying to persuade the people, are the regime's only enemies.
And they, too, would be crucial members of Greene's cast.
That roster might include Milad Hussein, a lean white-haired and erect military spokesman in his 50s who has just a hint of the Maoist, in dress and ideological certainty. Hussein is also the officer in charge of "revolutionary courses and moral guidance" for the armed forces, a man honest enough in his own way to admit – amid all the propaganda about al-Qa'ida and foreign fighters – that many of those who seized weapons from military bases were Libyans who knew where to look from their own military service.
It might include the relentlessly cheerful figure of Majdi Daba, a 42 Libyan dentist turned trainer of Ukrainain racehorses an ultra-patriotic Gaddafi supporter despite his long absence from the country. Mr Daba did not go on, as many less excitable Gaddafi supporters do, to stress Libya's free education and healthcare. Instead he made the startling assertion that "I love him because he has made a free nation."
Sure enough, in the traditionally furnished Dar Yazarkhon shisha and tea house, there is no obvious disquiet. Set just back from the sea front, no one is talking politics and the atmosphere, and the impeccably polite Malian waiter, are both pleasantly calm. The television is showing football at low volume. "Everything before the bombing was 100 per cent," insists one patron. "But now you can see people are subdued."
But trumpet Gaddafi's "freedom" to the civilised shopkeeper, who actually gives his name, and, provided no Libyan is listening, he will tell you that he too supports the no-fly zone, that Gaddafi is a "disaster" and that the "volunteers" are poor boys from the Buslin and Hadba districts who need the money. "All professional people, doctors, engineers are against him. If this [the international military intervention] goes on for a few days, his defences are knocked out, and if the people come from the east, then the people here will do something. But everyone is silent because they are afraid."
As well they might be when Human Rights Watch has recently reported an unknown number of arrests of oppositionists across the city, and their unknown fate.
The shopkeeper's series of "ifs" are big ones, as he knows only too well. As we leave the souk, a black market money changer asks us where we're from. "Tripoli is calm, you see. Just like London," he says with a smile. Well yes, the London of The Confidential Agent, perhaps. Or A Gun For Sale.