The play starts on the main square of Verona where two childhood friends, Valentine and Proteus, saying their emotional farewells, Valentine has to go to Milan and desperately wishes Proteus to go with him. Proteus would be happy to do so, but there is someone in Verona he can’t leave alone: his beloved Julia. Proteus promises to pray about Valentine, but Valentine says that he should save the prayers for himself, because the risks of love are much higher than the risks of travelling. Valentine departs and Proteus laments that he has to betray his friendship because of his overwhelming passion for Julia. Suddenly, Valentine’s servant arrives. Proteus asks him if he delivered his letter to Julia, but doesn’t get the exact answer. When the servant leaves, Proteus decides to send another messenger with a letter, just to be sure.
We see Julia talking to her maid Lucetta about her admirers. Julia names almost all the best young men of Verona and Lucetta sarcastically exposes their flaws. Proteus is named the last and he is the only one who didn’t propose to her yet. Julia receives a letter from Proteus, but pretends to be indifferent before the servant. Once the servant leaves, Lucetta brings back the letter she pretended to throw away and starts kindly mocking her mistress for such contradictory actions. The girls have an argument and finally enraged Julia tears the unopened letter to pieces. Lucetta leaves and Julia, lamenting her temper, starts putting the pieces back together. Unable to restore the whole letter, she reads some words of love and hides these pieces in her dress. Lucetta returns, saying that Julia’s father waits her for dinner.
The next scene is in the Proteus’ home. His father talks to the servant, thinking over the possibility to send his son abroad to study. He decides to send him to Milan to join his friend and also learn some useful skills at the Milanese court. Proteus enters, reading the letter from Julia. His father asks what he is reading and Proteus, embarrassed, lies that he received a letter from Valentine and his friend invites him to join him. Proteus’ father says that he was just thinking about it and will send Proteus to Milan on the next day, not to keep friends apart for long. Later, alone, Proteus bitterly regrets his lie that now parts him from Julia.
The narrative shifts to Milan, where Valentine’s servant accidentally brought him the glove of the Duke’s daughter Sylvia Valentine is hopelessly in love with. The servant says that this lovesickness was obvious, despite Valentine’s panicked denial. Valentine confesses that Sylvia asked him to compose a love poem he struggles with for a long time. Suddenly, Sylvia enters and Valentine frantically explains that the poem she asked for is almost ready, he is just dissatisfied with the lack of eloquence in it. Sylvia, nevertheless, has a look, compliments the poem, but asks Valentine to pay more attention not to the eloquence but to his true feelings. Sylvia leaves and the servant sarcastically remarks that she obviously is teaching Valentine how to write a proper love letter to her. Valentine, though, as most of the lovers, stays oblivious to it.
The next scene is again in Julia’s house. Proteus comes to say farewell to her, promising to return from Milan as soon as possible. They exchange rings as the symbol of their devotion. Finally Proteus is sure that she loves him and leaves content. On the street Proteus’ servant also says farewell to his friends and family - he has to depart with his master. The second servant comes and the tearful scene turns to a comic relief while both men are following Proteus.
Meanwhile in Milan Sir Thurio, the suitor chosen for Sylvia by the Duke is furious because of Sylvia’s affection to Valentine. Thurio and Valentine compete with each other in the battle of wits in front of Sylvia, trying to impress the lady and Valentine wins, but Thurio compliments her instead. The sudden news comes from Valentine’s father: Proteus is going to arrive soon. Valentine praises Proteus, advertising his virtues and goes so far that Duke decides that he could be a good suitor for Sylvia too. When Valentine is left alone with Sylvia he tells that Proteus is already in love with another girl, but Sylvia playfully says that she has already seen the suitors who forgot their previous love while seeing her. Sylvia leaves to Duke and Thurio and enters Proteus. The friends heartfully greet each other and Valentine apologizes for mocking his friend’s feelings for now he feels the same to Sylvia. He said that if Sylvia is forced to marry Sir Thurio, they will elope together. Having Proteus’ promise to help, Valentine leaves. Proteus stays shocked, feeling that his love to Julia has vanished at the moment he saw Sylvia. He realizes that he is going to betray both his friend and his fiancée, but he can’t do anything with the temptation. He decides to tell the Duke about Valentine’s intentions, hoping that Duke will kick him away, clearing the road to Sylvia’s heart (while she obviously doesn’t love Sir Thurio).
Meanwhile in Julia’s house Julia tells Lucetta that she decided to go to Milan too to be with Proteus. Despite Lucetta’s warnings, the girl is adamant. So, Lucetta gives up and the girls discuss their disguise of two young men. Lucetta carefully warns Julia that Proteus may not be as desperate to see her as she is, but Julia doesn’t want to hear.
In Milan Proteus is granted the audience with the Duke and tells him everything about Valentine’s intentions, pretending to be very upset with such an indignity of his friend. The Duke thanks Proteus and says that he is now keeping Sylvia in the separate tower and he is the only one to has the key from her chambers. Proteus tells that Valentine thought to use the rope ladder passed to Sylvia and leaves, content. The Duke starts examining everyone going to Sylvia, but Valentine has only a bunch of letters instead of the rope. The Duke says to him that he is going to order Sylvia marry Sir Thurio. Valentine congratulates him, thinking only about his night plan. The Duke plays anger, saying that the daughter is disobedient and asks Valentine for advice. Valentine suggests gifts, but when the Duke says that Sylvia rejected his gifts, blatantly advices him to ignore her refusals and continue to persuade her. After tricking Valentine into conversation, the Duke catches him off guard and removes his cloak, revealing the rope ladder. The Duke takes Valentine’s letters and reads one of them aloud, revealing that it is the promise to free her this night. The Duke immediately orders Valentine to leave his court and Milan and threatens him with death if ever Valentine would be seen there again. The Duke leaves and Valentin cries for his broken heart, saying that death is equal to life without Sylvia. But finally, he leaves Milan.
Proteus finds him asking what happened. Valentine, oblivious to his friend’s betrayal, tells him everything. Proteus tries to comfort him, promising to pass his letters to Sylvia and care for her while Valentine is exiled. He also tells that Sylvia pleaded her father to spare her lover but it only enraged the Duke more.
The Duke in the meantime talks to Sir Thurio, telling him that his main rival is exiled. Sir Thurio replies that Sylvia is very upset now. Proteus enters and Duke asks him if Valentine is gone, sadly admitting that his daughter loved him. Proteus says that her grief is temporary. Duke asks Proteus to visit her and to be a mediator in this family conflict, helping her forget Valentine, because Sylvia refused to see Sir Thurio. Proteus gladly agrees, hoping to woo Sylvia for himself. To maintain his disguise he asks Sir Thurio to compose love poetry for Sylvia. Duke highly appreciates this advice and Sir Thurio enthusiastically starts writing.
The fourth act starts near Mantua, where a gang of thugs in the forest is hunting travellers. They stop Valentine and his servant and try to rob them, but Valentine explains that he doesn’t have anything because he was just exiled from Milan. It appears that the thugs share the same fate, so they ask what for he was exiled. Valentine lies that he killed a nobleman in a duel and wins the respect of the gang. They offer him a commanding position in the gang - or an execution if he refuses. He has no option than to agree, but his first rules are not to rob women and poor.
Meanwhile in Milan Proteus complains that despite his treacherous plan he didn’t win Sylvia’s friendship. Moreover, when he tried to confess to her, Sylvia bitterly berated him for his disloyalty to Julia. Still, he is going to keep trying. Sir Thurio comes with musicians to sing a serenade to his beloved. Julia, disguised as a young man, appears in the garden too, invited by the Duke as a page. She starts a small talk with Proteus’ servant, while Sir Thurio is singing and asks him if he ever came to Sylvia. The servant replies that his master is completely lovesick and visits her daily. Sir Thurio leaves and only then Sylvia looks down and thanks Proteus, thinking he is the one who sang. Proteus declares his love again, but Sylvia says that her only wish is that he leaves her alone and returns to his Julia. Proteus replies that Julia is dead (to the shock of disguised Julia) and adds that Valentine is probably dead too. Sylvia refuses to believe it.
Suddenly a new character, a knight-errant named Sir Eglamour appears. He has heard about the beautiful lady in distress and asks her if he can help. Sylvia says that she believes him because she knows he is faithful to the memory of his deceased beloved, so she asks him to free her and escort her to Mantua where she hopes to find Valentine. They agree to meet in the church where she is still allowed to go.
The next scene shows us Proteus who employs Julia in disguise as his messenger to Sylvia. He gives Julia her own ring and says that once it belonged to his love and now he wants it to be given to Sylvia. The “page” asks if his lady is dead. When Proteus replies that she is alive, Julia expresses pity to her, saying that she should still love and suffer. Proteus ignores these remarks and just orders Julia to go to Sylvia and give her the ring. He goes away, leaving Julia to wonder how she became a messenger to her own rival. But instead of hating Sylvia, Julia decides to talk to her and learn her true intentions. When she comes to Sylvia with the ring and a letter from Proteus, Sylvia tears the letter apart and returns the ring, saying that she knows its story and will never take such a gift that once belonged to the poor scorned lady. The “page” sincerely thanks her and when Sylvia wonders why he reacts this way, the “page” replies that he knows that lady like himself. He describes her appearance, praising her beauty. Sylvia is deeply interested and listens, until it’s time for “page” to leave. Having left, Julia thinks aloud about her compassion to poor Sylvia and her love to treacherous Proteus. She concludes that they have equal beauty, so she still can compete for Proteus’ love.
At night at the friar’s cell Sir Eglamour is waiting for Sylvia. She promptly appears and they sneak out of the castle to the forest.
Next day in the palace Sir Thurio asks Proteus how it’s going with consoling Sylvia. Proteus claims that she is almost ready, but mentions some flaws of Sir Thurio he may correct to appeal to her better. The Duke enters asking the rest of the cast about his daughter and Sir Eglamour. Soon they discover that they both escaped the castle and the friar says that they were heading to the forests. The Duke immediately orders Sir Thurio and Proteus to go after them and return his daughter. Sir Thurio is furious, berating Sylvia for escaping the marriage with such an awesome man as he is. The “page” also joins them, hoping to help Sylvia escape.
The narrative shifts to the Mantua forest. We see Sylvia captured by the thugs. They treat her with respect and we learn that Sir Eglamour managed to escape. They escort the lady to their captain (Valentine), who is now alone, thinking about his lost love and not interested now in the business of his men. Suddenly he notices Proteus, Silvia and the “page”. Seeing Sylvia as a hostage of thugs, Proteus rushed to help and saved her, now demanding anything in reward from her. Shocked, Valentine listens to the conversation and the angry refusal of Sylvia to ever talk to such a treacherous man as Proteus, a traitor to both Julia and Valentine. Fed up with her words, Proteus tries to forcefully bring Sylvia to him. Valentine steps out of the shadows and reveals himself.
Seeing his former friend, Proteus realizes the depth of his fall and begs his pardon. Valentine, too glad to see his love again, accepts the apology and then says to Sylvia that she is free to choose anyone. Julia, imagining that Sylvia will now choose Proteus, faints. Both men come to aid the “page” and he apologizes, saying that he was too tired and ashamed, because he hasn’t given the ring his master ordered him to give to Sylvia. Julia gives the ring back to Proteus - but he suddenly realizes that it is the other ring of the pair, the one he gave to Julia. Finally he understands that the “page” is actually Julia, who endured dangers and losses, and risked her life just to be with him. Her love and determination touches him so much that he immediately apologizes again, declaring his eternal love to Julia.
Suddenly the thugs bring in the rest of the rescue team: the Duke and Sir Thurio. They are glad to capture the Duke himself, but Valentine orders to set him free, to their displeasure. The Duke now owes Valentine his life and agrees to give Sylvia’s hand to him. Sir Thurio cowardly refuses to fight for Sylvia’s affection. The Duke offers everyone to return to the palace and start preparations for the marriages. Valentine asks for the single wedding gift: a pardon for all his transgressions. The Duke immediately grants his pardon. They all return to Milan and finally marry, living together happily ever after.