In pursuit of amorous adventures on his master's behalf Caramello has learned with interest from Pappacoda that a gondolier is due to take Barbara Delacqua to Murano at 9 p.m. What he does not know is that his own girlfriend, Annina, has been persuaded by Barbara to take her place in the gondola, so that Barbara may spend her time with Enrico Piselli. Annina is determined to be back within the hour so that she may join in the Carnival dancing with Caramello, Pappacoda and Ciboletta in masks borrowed from their masters.