L’inganno felice, farsa in un atto to a libretto by Giuseppe Foppa, was first produced at the Teatro San Moisè, Venice, on 8th January 1812. The singers of the first performance were Raffaele Monelli (Bertrando), Teresa Giorgi-Belloc (Isabella), Vincenzo Venturi (Ormondo), Filippo Galli (Batone), Luigi Raffanelli (Tarabotto).
In a remote district where mining is carried out, Tarabotto, the head of the miners, learns from his men that the Duke Bertrando, the lord of the neighbourhood, is unexpectedly arriving, and his military escort can already be seen in the distance. Isabella comes in; she is a young woman whom, ten years earlier, Tarabotto had found cast up on the shore and apparently lifeless after the capsizing of her boat at sea. Since then he has afforded her the shelter of his home, introducing her to everyone as his niece Nisa. Although he has no idea of her true identity, Tarabotto has never tried to intrude upon her privacy, but now, seeing her overwhelmed with sadness and noticing that she is clutching a portrait of the Duke himself in her hands, he is spurred on to question her by the desire to know why she weeps and sighs over the portrait, uttering words that seem very suspicious to him. Yielding to the repeated urgings of the man who has earned her deepest gratitude, Nisa lets him read a letter that she has written to Bertrando. In this letter, Isabella declares that she is the Duke’s legal wife, proclaims her own innocence and informs him that she is still alive, though the victim of the treachery of Ormondo, a powerful follower of the Duke’s who, having decided to be revenged upon the Duchess, who had repulsed his amorous overtures, had managed to convince Bertrando, by his lies, that his wife was unfaithful to him; he then ordered his henchman Batone to cast her afloat on a tiny boat at the mercy of wind and wave. Tarabotto, disconcerted by this news, bows respectfully to his Duchess, who can now fully reveal to him what she intends to do. The Duke, in fact, certain of the unfaithfulness and of the subsequent death of Isabella, had married again, but his second wife has recently died. For Isabella, therefore, Bertrando’s visit to the mine represents an unhoped-for opportunity to see her husband again, a circumstance that fills her with the rosiest hopes.
The Duke comes in, still brooding over memories of his first wife. This, however, is hardly the time for indulging the heart’s fancies: Bertrando has, in fact, come to this outlying spot to checkmate the threats of war on the part of the lord of the neighbouring territory by a surprise attack, taking advantage of a little-used frontier passage. To put his plans into effect he intends, following a suggestion of Batone’s, to profit from Tarabotto’s uniquely exhaustive knowledge of the terrain, and so he asks him to be his guide in a brief reconnaissance. Meanwhile, Batone asks Nisa to give him something to drink: the woman immediately recognizes her old enemy who, in his turn, is struck by the distressing conviction that she looks like his victim of long ago, and falls prey to anguished doubt and suspicion.
Tarabotto returns to tell Isabella that the Duke is about to arrive at their house to consult a map of the mines. Isabella is trembling with the emotions aroused by the idea of this meeting but Tarabotto tries to give her courage: now she must be brave and get control of the situation, now she must keep an eye on the actions of Ormondo and Batone, another knave of the same stamp. Bertrando comes in: Tarabotto asks leave to introduce his niece, who will explain the maps to him. Isabella approaches him, fearing that he will not recognize her after all, but the Duke has but to see her and hear her voice to begin to feel deeply conflicting emotions that leave him full of loving feelings for her. Tarabotto is a contented witness of what is going on: the two repeatedly glance at one another only to look quickly away again; Isabella cannot decide whether she should go or stay; Bertrando, uncertain whether to ask her to go or beg her to remain, asks her to allow him to gaze upon her a little longer, for he fears that he is the victim of an illusion. At last Isabella goes back indoors, leaving Bertrando alone with his thoughts. All the Duke can do is ascertain that his first wife really did die: he questions Ormondo, who in his turn asks Batone what really took place, and orders his henchman, on pain of death, to carry off Nisa during the night and so get her out of the way and prevent any unwelcome developments. Batone tries to wheedle information about Nisa’s identity out of Tarabotto: whilst each of them is too cunning to give himself away, Tarabotto guesses that his guest is in some kind of danger and puts her on her guard. Bertrando joins them and begs Nisa to tell him the story of the troubles, and recognizes that the treachery from which she suffered is a case very similar to his own. Tarabotto, who has decided to inform the Duke personally of Ormondo’s sinister designs upon Isabella, begs him to award his protection to his niece, who is in danger from some unknown rogue. The Duke, by now deeply in love with Nisa, eagerly accepts.
Now it is night: Isabella is hiding near Tarabotto’s house; he has made her put on the dress that she was wearing when she was shipwrecked. With his followers, Bertrando lies in wait by the entrance to the nearby mine. Batone is first to arrive, entering the house with a band of armed men; he is quickly followed by Ormondo, who has come to supervise Batone’s grim task, only to discover from his henchman that the house is empty. Unable to believe his ears, he goes in to check the matter personally. Bertrando, who from his hiding-place has been able to observe everything, seizes the opportunity to come out into the open, catch Batone red-handed and force him to collaborate, hoping to make Ormondo confess his misdeeds. He then goes back to his hiding-place. Having been caught, Batone has no choice but to collaborate: when Ormondo comes out of the house in a rage, Batone asks him why he wants to try to kidnap Nisa. Ormondo tells him that he wants to kill Nisa because she reminds him too much in her looks of the Duchess who had rejected his advances and perhaps she might reveal to the Duke all his intrigues of long ago. Bertrando, who has overheard everything, rushes out of the mine with his soldiers, invoking the name of his lost wife and offering to sacrifice his own life if only she will forgive him. Tarabotto and Isabella rush to stay his hand; Isabella is alive, she is here beside him, and she can prove her identity by means of the dress she is wearing and by the Duke’s portrait, which she has always so jealously guarded. Having been forced to act under the threat of death, Batone is forgiven his part in the attempted murder of the Duchess; the treacherous Ormondo, on the other hand, is led off to prison, whilst husband and wife are at last happily re-united.