Having arrived at Milford-Haven where Imogen will supposedly rendezvous with Posthumus, Cloten draws his sword and waits. He is attired in Posthumus’ garment with which he is determined to make Imogen regret that she had ever said that she finds Posthumus’ meanest garment more valuable than anything Cloten possesses.
Seeing how Fidele isn’t feeling particularly well, Polydore and Cadwal urge him to return to the cave and rest. Indeed Polydore offers to stay and attend to Fidele who persuades him otherwise, arguing that he isn’t so sick as to warrant being attended to. So Fidele returns to the cave where he takes some of the medicine Pisanio had given him, while Polydore, Cadwal, and Morton go to attend to their daily hunting exercises. They are thus on their way, speaking highly of Fidele when they encounter Cloten who Morton recognizes from his days in Cymbeline’s court. Sensing danger, Morton advises that they make themselves scarce, but Polydore insists on confronting him and does so while Morton and Cadwal do reconnaissance to see if there are others, belonging to Cloten’s party, about. When Morton and Cadwal return, they are met by Polydore who has beheaded Cloten, making Morton extremely anxious. Polydore is vindicated, however, as it was Cloten’s head or his and as Cloten himself had instigated the deadly duel, which vindication Cadwal seconds. Resigned to the fact that what’s done is done, Morton orders Polydore to fetch Cloten’s body for burial, while Cadwal is sent ahead to join Fidele in the cave where they are to make preparations for dinner.
It isn’t long when Polydore returns with Cloten’s headless body that he and Morton hear music emanating from the cave which music hadn’t been heard since Euriphile’s death--Euriphile who was Polydore’s and Cadwal’s nurse who Morton had the children believe was their mother. Presently, Cadwal appears, carrying the seemingly dead body of Fidele. They vow to give it the most beautiful burial. Mouthing the words to a song that they sang when Euriphile died (mouthing it lest their sorrow mar the song), they dig Fidele’s and Cloten's open grave and gather flowers and herbs which will prevent wild animals from desecrating the corpses. Their obsequies done, they leave.
Fidele awakes to find herself slumped over Cloten’s headless body. On account of Posthumus’ garments, Imogen believes that the corpse is Posthumus‘. He curses Pisanio who she believes has conspired with Cloten to bring matters to this state. She recalls that it was Pisanio who had given her the medicine the effects of which are more like poison than medicine. She wonders what rewards Cloten had promised Pisanio for him to have betrayed both Imogen and Posthumus. She is thus cursing Pisanio and Cloten and lamenting her fate when Caius Lucius, who is accompanied by captains and a soothsayer, approaches from nearby. One of the captains informs Lucius of how the Roman armies that were garrisoned in Gallia have arrived at Milford-Haven, of how the nobles of Rome will be providing Lucius with whatever support that he may require, and that the man who will be acting as the nobles’ representative will be Jachimo. The soothsayer assures Lucius that his enterprise will be a success when Lucius spots a boy slumped over a headless body. The boy, who is found to be alive, is questioned about the matter. The boy tells Lucius that the identity of the corpse is Richard du Champ, and that savage mountaineers have taken his-the boy’s--master’s life.
Sympathetic, Lucius asks Fidele if he would like to work as his--Lucius‘--attendant. Fidele says that he does, but not before he has given his master a proper burial.
Cymbeline is in a state of extreme duress as everything seems to be going wrong at the worst possible moment. War with the Rome is an inevitability and to compound the crisis, his daughter, his sole comfort in the world, is missing. As for the Queen she is sick in bed due to Cloten’s mysterious absence thus depriving Cymbeline of much needed advice with regards the Roman threat. Cymbeline suspects that Pisanio is hiding something and would have him tortured but for a Lord who vouches for him.
For his part, Pisanio is terribly worried too as he has sent word to Posthumus of Imogen’s death but has heard nothing in reply. Likewise he hasn’t gotten any word from Imogen who had promised to keep him diligently posted on her progress.
The coming war with the Romans is so palpable that even Polydore, Cadwal, and Morton must make a decision with regards its approach. Morton wants to go higher up into the mountains where they’ll be able to avoid all entanglements with either the British or the Romans. Polydore and Cadwal are eager to fight with the British fighting forces however. They argue that though Morgan may be recognized and be imprisoned by Britain, no one will recognize Polydore and Cadwal. They are so eager that Morton can’t help but to let them go and prove their mettle. Indeed, Morton resolves to join them and live or die fighting besides them.