Nemorino, a simple soul with more heart than sense, is hopelessly in love with Adina, the town’s “it” girl. Adina, who definitely needs to get over herself, entertains the town by reading the story of Tristan and Isolde’s love potion and gets herself engaged to a visiting sergeant merely, as far as anyone can tell, to spite Nemorino. Nemorino procures the help of Dr Dulcamara, a less-than-honest traveling purveyor of quack medicines, one of which just happens to be, after Nemorino makes a very specific inquiry, the very same love potion used by Queen Isolde. Dulcamara is, indeed, the manufacturer. But “the authorities” take a dim view of this particular drug and Dulcamara advises Nemorino to keep his mouth shut. It’s actually a bottle of cheap claret on which Nemorino promptly gets thoroughly buzzed. Dulcamara never sticks around long: he expects to be long gone before anyone finds out.
A snafu in Belcore’s orders requires that the marriage be moved up to that very evening, before the effects of the ‘potion’ are to kick in. Despairing, Nemorino enlists in Belcore’s regiment merely for the signing bonus, which he uses to buy a second dose. Meanwhile, the girls of the village come to know that Nemorino’s rich uncle has died leaving him millions. Nemorino is now the most eligible bachelor in the district. Dulcamara’s love potion may not work, but a bank account with lots of zeros sure does. Adina, who — much to Belcore’s annoyance — has been putting him off, comes face-to-face with Nemorino’s newfound popularity, and comes to see him in a new light.
It all ends happily with Nemorino and Adina hand-in-hand. Dulcamara knows a commercial opportunity when he sees one. Belcore shrugs and notes that there are plenty more fish in the sea.