Posthumus enters alone, holding a bloody handkerchief—the “proof” that Pisanio followed through with the order to kill Imogen. Posthumus promises to hold onto it because he once wanted Imogen dead, but now he regrets it. He exclaims that all the husbands who have their wives killed for “wrying but a little” are holding the women up to an impossible standard. These wives, he concludes, have better characters than their murderous husbands.
Posthumus’ behavior at the top of the play’s last act contrasts starkly with his behavior when he was last seen onstage, calling for Imogen’s death. His mood is absolutely repentant, and he gives women the benefit of the doubt, which is surprising in light of his misogynistic ranting. Posthumus’ speech will set the tone of repentance and reconciliation that dominates this act.
Posthumus then addresses Pisanio (who’s not onstage), laying some of the blame on him, since servants should know better than to follow unjust orders. He derides servants who blindly follow all their master’s commands, because their duty should be to comply with only the “just” orders.
Ironically, Posthumus criticizes Pisanio for following unjust orders. In fact, Pisanio disobeyed his master’s unjust orders, refusing to kill Imogen as Posthumus commanded. He has proved loyal through that deception, though he has also tricked Posthumus by sending the bloody handkerchief, which he’ll have to answer for.
Next, Posthumus calls out to the gods. He claims that he is such a terrible sinner that if the gods had really avenged all of his misdeeds, then he would never have lived long enough to have Imogen killed. In addition, since the murder he ordered was unexpected, he wishes that Imogen would have had time to repent. He hopes that he will be killed, because he thinks he deserves it more than Imogen.
Posthumus demonstrates considerable piety at this point. He asks for divine retribution for his crimes and puts stock in the power of repentance before death—a practice particularly important in Shakespeare’s time (allowing the soul of the dying the chance to get to heaven).
Posthumus comforts himself with the fact that Imogen is with the gods in peace, away from the cruel world. He asks the gods to do what they will with him, and promises to obey them.
Though he’s called on the gods before in this play, Posthumus’ tone is absolutely remorseful—a stark contrast to how he’s acted previously.
Posthumus explains how he has come back to Britain. Italian nobles brought him to fight on the side of the Roman Empire against Britain—his wife’s homeland and the place where he grew up. But Posthumus feels like he has done enough violence to Britain by ordering the murder of its sole heir and future ruler, Imogen. Therefore, he decides to discard his Italian clothes and disguise himself as a British peasant instead. All signs point to a Roman victory, and Posthumus vows to die fighting for Imogen’s country, begging the gods to give him strength. As for the peasant’s clothes, Posthumus will subvert expectations: he won’t seem noble by his appearance, but instead his actions will be noble. Posthumus leaves for battle.
Posthumus hopes to right his wrongs by fighting on behalf of the British. In so doing, he hopes to rectify a dire situation—leaning, of course, on the gods for their help. After asking for divine justice, he plans to execute justice on the earthly plane through his efforts in the battle. He also confirms a key point in the play—that noble behavior doesn’t necessarily align with social status or a high-born appearance.