It is an evening in eighteenth-century Venice. In a square on the Grand Canal, with a view across to the Ducal Palace and the Isle of San Giorgio, people stroll around as the sun goes down, while the tradeswomen call out their wares. The young Neapolitan macaroni cook Pappacoda observes that, for all the splendours of the city, Venetians do not have everything without their macaroni cook. "Macaroni as long as the Grand Canal, with as much cheese as there is sand in the Lido" – that is what Pappacoda offers. The young man is approached by Enrico, a naval officer, enquiring whether the Senator Delacqua is at home. When he is told that he is at a sitting of the Senate, Enrico sees it as an opportunity for a few private minutes with the Senator's young wife Barbara. However, she also is out, so Enrico slips Pappacoda a coin to give Barbara a letter with the message that Enrico will be ready for her at nine o'clock that evening.