Valentine sets off from Verona for Milan to see the world.
Proteus stays at home because of his love for Julia. She is in love with him, but neither knows of the other's love until Lucetta shows Julia a love letter from Proteus. He is reading her reply when his father, Antonio, sends him to the Duke's court to join Valentine. The lovers take their leave and swear eternal constancy.
Proteus finds that Valentine has fallen in love with Silvia, the Duke's daughter, and plans to elope with her to foil her father's plan to marry her to Turio. Valentine confides his plan to his friend but Proteus, infatuated with Silvia at first sight, betrays the plan to the duke and Valentine is banished from Milan.
Valentine in the wilderness, Proteus in Milan
Valentine encounters a band of outlaws in the wilderness and is elected their leader.
Meanwhile Julia, disguised as Sebastian, arrives in Milan in search of Proteus. Overhearing him declare his passion for Silvia, she is devastated but, under cover of her disguise, enters his service as a page.
Julia is encouraged to find that Proteus' are again rejected and Silvia remains faithful to Valentine.
Stop reading now if you don't want to know how the story ends ...
Silvia escapes into the forest to join Valentine. The Duke and Turio set out in pursuit, followed by Proteus and Julia. Silvia is captured by the outlaws but then rescued by Proteus who, seeing that she still spurns him, tries to force himself on her.
Valentine intervenes and Proteus is forced to confront his act of betrayal. Julia reveals her identity and reconciliation begins.