Act 1
A group of shepherds and shepherdesses celebrates the idyllic life in Arcadia. They are joined by the semi-divine water nymph, Galatea, who is in love with Acis, a mortal shepherd. She is overwhelmed by desire and instructs even the birds to stop singing as it serves only to intensify her longing for him.
Elsewhere, Acis is searching for Galatea. The spirit Damon warns him of the dangers of becoming the lover of a goddess while reminding Acis of the pleasures of Arcadia which are open to him.
Acis and Galatea are reunited and despite the potential dangers of their liaison they find perfect happiness in their relationship.
Act 2
The chorus reminds us that all mortal happiness is finite. As though to illustrate this point, the giant Polyphemus comes stalking though the forest, intent on having Galatea for himself, but she arrogantly rejects his advances. Damon mischievously plays Polyphemus and Acis off one another in their desire to possess Galatea.
Acis attempts to defend Galatea against Polyphemus but she stops him, realizing the futility of his determination. Polyphemus in a fit of jealousy hurls a rock at Acis and kills him.
The shepherds and shepherdesses mourn the death of Acis and are joined in their lamentations by Galatea. They remind her to exert her divine powers in an attempt to save him. Galatea cannot bring Acis back to life but she is able to transform him into a fountain in which she, as a water nymph may live and which will in turn sustain the inhabitants of Arcadia.
