Once there, her task is to find out anything and everything she can about "Ceausescu's Gold" - the millions of dollars Romania's late dictator is believed to have stashed away in Swiss bank accounts just before his fall.
Afternoons of passion in the Bucharest penthouse she would persuade him to buy her were to be followed by gentle probing as to the real intentions of ex-King Michael, the former Romanian monarch now exiled in the ambassador's Swiss homeland.
And far from keeping the affair discreet, the agent is to make sure that she and her consort - a married man with two children - are frequently seen together wining and dining in public and at diplomatic functions. Just for good measure, the exercise will be called "Operation William Tell".
In a country where rumour, counter-rumour and conspiracy theories abound, such a scenario could normally be consigned to the scrap heap of fantasy. But, for a change, some of it is certainly true. Not in any doubt is the fact that Jean-Pierre Vettovaglia, 49, until recently the Swiss ambassador to Bucharest, enjoyed a year-long affair with 21-year-old Floriana Jucan, a political journalist.
And when details of the liaison were published last month in the Romanian press, Mr Vettovaglia was relieved of his ambassadorial duties and recalled to Berne for urgent questioning.
More controversially, in a terse statement confirming the recall, the Swiss foreign ministry said its own investigation had concluded that the red-headed Miss Jucan was "an employee of the Romanian espionage service" and that her relationship with the former ambassador had "posed a security risk to Switzerland".
In addition to "abuse of office", Mr Vettovaglia is to be investigated for falsifying documents: expense claims allegedly used to buy furniture for his lover's flat.
For the Swiss, the scandal - unprecedented in the post-war diplomatic history of the country - has been nothing short of sensational, avidly reported under such headlines as "(S)ex-ambassador!" and "Ambassador succumbed to the charms of a spy!"
Romanians have also lapped up the salacious aspects, but some have questioned the central charge against Miss Jucan. Not surprisingly, she herself denies it: "I do not belong to any information service," she says. "If I am guilty of anything it is that I love this man... and he loves me too."
The official Romanian Intelligence Service (SRI), for its part, has disclaimed any knowledge of her, while the foreign ministry expressed regret over the departure of Mr Vettovaglia, a man praised for his high degree of "competence and professionalism".
But her protestations of innocence took something of a knock this week with the publication of a photograph appearing to show her hand-in-hand with the Israeli Prime Minister Shimon Peres and within striking distance of Palestinian leader Yasser Arafat.
The picture in satirical magazine Academia Catavencu, was taken during a 1994 conference in Bucharest. According to the magazine, her proximity to the two leaders - a privilege not granted to any other journalist - would have been impossible without the blessing of the secret service.
That permission was given was extraordinary: firstly, at the time she was just a 19-year-old cub reporter and secondly, she was then working on Romania Mare, a rabidly anti-Semitic weekly.
In the febrile atmosphere of post-Ceausescu Romania, where some still see Securitate secret policeman on every street corner and where the mystery of the missing millions in Swiss bank accounts has never been solved, some have already interpreted the photo as evidence of a wider plot.
Perhaps not surprisingly. In addition to the SRI, there are said still to be hundreds of spies floating around Bucharest, some reporting to the interior ministry, some to the foreign ministry and others to the presidential guard.
And some have undeniable charms. "Whenever there is an official party, there always seem to be pretty girls hanging around who do not appear to have any relevance to the function," confirmed one western diplomat.
Whatever the rumours, Miss Jucan does not intend to be put off her stride. If charges are levelled against Mr Vettovaglia, she intends to fly to Berne to be by his side and testify in his defence.
Longer term, she plans a book on her life and loves, including billets doux from the amorous ambassador. There will be other revelations, too, according to her literary agent- including one of the world's leading foreign ministers "drunk with his pants down".