At the end of act one of Mozart's Don Giovanni the great seducer is confronted by his adversaries.
But even though there are five of them, one armed with a pistol, he escapes, singing all the while.
Towards the close of Bram Stoker's Dracula, there is an equally implausible scene. The anti-hero's persecutors - again five in number and this time all armed - lure him to a house in London.
He succeeds in evading them by jumping through a window.
Coincidence? Or something more?
An article published yesterday on the front page of one of Italy's leading national newspapers draws attention to some remarkable parallels between the story of Stoker's seminal Gothic villain and that of the archetypal Latin cad depicted in Lorenzo Da Ponte's libretto more than 100 years earlier.
The article's author, the Turinese critic and novelist Alessandro Barrico, does not go so far as to claim that the vampire count was modelled on opera's most dastardly lady-killer.
But in yesterday's La Repubblica he writes: "Perhaps Stoker had an obsessive love of Don Giovanni. Perhaps, in some hidden corner of his mind, the opera continued to work on him subconsciously, dictating to him various models and devices."
Both works are about seducers, though of different kinds, and the erotic connotations of Dracula's vampirism have been picked up on many times by critics and film-makers.
Other similarities between the two works became clear to him, Mr Barrico says, as he was listening to Mozart's opera and was struck by the way in which the central character, like Stoker's Count Dracula, was conspicuous by his absence.
"The [other characters] are personalities. He is little more than a force. Everyone speaks about him obsessively ...
"He, on the other hand, scarcely exists. He has no comprehensible psychological profile."
Among other parallels noted by Mr Barrico are:
· Both anti-heroes claim three 'victims' (the peasant girl Zerlina, Donna Elvira and Donna Anna in the case of Don Giovanni; Lucy Westenra and Jonathan and Mina Harker in the case of Dracula);
· Each is faced by enemies who include two pairs of lovers and an elderly man;
· Both have parallel master-servant relationships (with Leporello and Renfield, who both complain of being denied the pleasures enjoyed by the central characters);
· Apart from the seduction of the peasant girl Zerlina, all the significant developments in Mozart's opera, and particularly Don Giovanni's sexual assaults, take place at night;
· When he seduces Donna Anna, he does so wrapped in a vampiresque cloak. She wakes up as if from a dream, in the same way as Lucy does after being attacked by Dracula.
Mr Barrico also notes that Mozart's opera features a character from the ranks of the "undead". Donna Anna's father, the Commendatore, has enough vampire-like attributes to return to life after his murder and drag Don Giovanni down to hell.