Summary
In Milan, Valentine and Silvia – the Duke's daughter – have fallen in love, and are exchanging letters between one another.
Proteus and Julia, meanwhile, bid each other a tearful goodbye as Proteus prepares to leave Verona. Proteus vows that a ring Julia gave him will forever remain a symbol of his devotion to her.
Proteus's servant, Launce, explains to Proteus how he thinks his dog, Crab, is the most ill-behaved and sour creature.
Proteus soon departs for Milan.
In Milan, Silvia is being pursued by an admirer named Thurio, whom the Duke has decided she will marry.
When Proteus arrives in Milan, Valentine is overjoyed. He eagerly shares with his friend his newfound love for Silvia and his plan to steal her away in the night. When Valentine departs, Proteus confesses that he, too, has fallen in love with Silvia.
Proteus decides to pursue Silvia, betraying both Valentine and Julia. He will tell the Duke about Valentine's plan to escape with Silvia, leading the Duke to banish Valentine from Milan.
Meanwhile, Julia entreats Lucetta to help her plan a trip to Milan so she can visit Proteus. Lucetta warns Julia that the journey is a dangerous one, and Julia resolves to dress herself in disguise as a high-class page. Lucetta expresses doubts over Julia's belief that Proteus is completely faultless, but ultimately agrees to help Julia with her disguise.
Analysis
Act Two of the play thrusts audiences into its central conflict: Proteus and Valentine each falling in love with Silvia, the Duke's daughter. It is through this conflict that the friends – once nearly as intimate as lovers – are quickly cast as enemies.
However, it is important to note that, in an example of dramatic irony that lasts for multiple acts of the play, it is only Proteus who perceives Valentine as his enemy. Valentine, by contrast, has no idea that Proteus has fallen in love with Silvia or that he (Proteus) is planning to not only prevent Valentine's marriage but also sentence him to banishment. The conflict between the two friends is therefore an unspoken one, with Proteus being cast as a type of villain as he resolves to, essentially, destroy his best friend's life.
This fickle nature of Proteus appears in stark contrast to Julia, who resolves to risk everything – even her safety – to be reunited with the man she loves. Ironically, Speed had expressed earlier in the play that it is women who are naturally fickle and untrustworthy. Through Proteus and his decidedly quick love for Silvia, however, one can see that the play gestures toward the fickle nature of men as well, even suggesting that the misogynistic outlook on women's fidelity it unfounded.
Julia, however, is not without her own form of deception. In this act, she and Lucetta devise a plan for Julia to dress up as the page boy, Sebastian. Many point to this plan as another precursor for Shakespeare's more famous comedies in which disguise – specifically cross-dressing disguises – play a crucial role in the development of the plot (Twelfth Night and As You Like It are the most noteworthy examples, as they both feature young women who dress as men in order to advance themselves).
It is important to note, however, that Julia decides to dress as a page boy for no other reason than to keep herself safe on the journey to Milan – a journey that, Lucetta warns her, will be marked by the unwanted advances of many men. This conversation introduces the threat of sexual violence to the play, something that lingers in the background around the female characters. Moreover, that Julia uses a disguise to protect herself – rather than to deceive – emphasizes the necessity of her scheme compared to that of Proteus. The two forms of "deception" are inherently contrasted with one another, as Julia deceives with her outward appearance and Proteus deceives with his inner moral transgressions.