Angelo apologizes to the merchant for making him wait for his money. He says that Antipholus is “of very reverend reputation” and usually good for his money. Antipholus of Syracuse enters with Dromio of Syracuse. Angelo sees his chain around Antipholus, and asks Antipholus how he can deny that he has the chain.
Confused, Antipholus says that he never denied it. The merchant swears that he did, and Antipholus prepares to duel to defend his honor. He and the merchant draw their swords, but then Adriana, Luciana, and the courtesan enter. Adriana says that Antipholus is mad and asks for help in tying up Dromio and him. Antipholus and Dromio flee to a nearby priory (a kind of monastery).
Antipholus of Syracuse is willing to duel over his honor, unaware that this whole dispute is the result of coincidences and his resemblance to his lost twin.
The abbess of the priory comes out to see what is going on. Adriana says that she wants to get her husband from the priory, as he is mad. The abbess asks what is wrong with Antipholus—whether he has lost money in a shipwreck, lost a friend, or has become adulterous. Adriana admits that the last one may be true. The abbess says that Adriana should have scolded him more for this, but Adriana says she did so all the time. The abbess says this is probably why Antipholus cheated on her: she nagged him too much.
Adriana admits to a possible problem in her marriage, and the abbess places the blame for Antipholus’ apparent infidelity on her. It says a great deal about the gender disparity of the time in that Adriana is made the scapegoat for the issue regardless of whether she scolded her husband too much or not enough.
The abbess refuses to let anyone into the priory, honoring Antipholus and Dromio’s right of sanctuary there. She says that she will bring Antipholus “to his wits again,” with “wholesome syrups, drugs, and holy prayers.” The abbess leaves, and Luciana suggests that Adriana go to the Duke to complain. Adriana agrees with the plan. The merchant notes that the Duke is due to come by this way anyways to execute a Syracusian merchant.
Like Adriana, the abbess thinks that Antipholus and Dromio are mad, when they are actually the victims of mistaken identity and a series of comic errors.
The Duke enters with Aegeon, and repeats his offer that if anyone can pay the fee for Aegeon, he will live. Adriana interrupts him to call for justice against the abbess. She explains that her husband Antipholus has gone mad and stolen things. She had him bound and sent home but he escaped and chased her and Luciana with swords. They then fled into the priory, where the abbess won’t let anyone enter. Adriana asks the Duke to have Antipholus brought forth so they can help him.
The Duke’s offer again establishes the importance of monetary exchange, which can save Aegeon’s life. Adriana narrates to the Duke her version of the day’s events, ironically unaware that she has continually mixed up her husband and his twin.
The Duke sends for the abbess, to get to the bottom of the matter. A servant arrives from Adriana’s house and announces that Antipholus and Dromio have escaped their binds and attacked Pinch. Adriana says that this can’t be true, as the two are in the priory. The servant insists he is telling the truth, and tells Adriana Antipholus is threatening “to scorch your face, and to disfigure you.”
Adriana doesn’t believe the servant, and treats him as a bit of a scapegoat, calling him a liar, because she doesn’t realize that she and the servant are each thinking of a different Antipholus. Antipholus of Ephesus continues to threaten violence against his wife, blaming for the mixed-up events of the day.
Just then, Antipholus of Ephesus and Dromio of Ephesus arrive, and Adriana is frightened. She exclaims that he “is borne about invisible.” Antipholus asks for justice. Aegeon says that he recognizes his son and his son’s servant, but no one listens to him. Antipholus tells the Duke that his wife shut him out of his own house. Adriana and Luciana both deny this, but Angelo says that he saw it happen.
Adriana resorts to another supernatural explanation for the coincidence of Antipholus and Dromio of Ephesus arriving just when she thinks they are in the abbey. No one can agree on what happened during the day, because of all the errors and mixed-up identities throughout the day.
Antipholus insists that he is not mad, and summarizes what has happened to him: his wife locked him out of his home; then, Angelo did not deliver him his gold chain, so he went to find him and Angelo said that he had already given it to him; he was arrested and sent Dromio to get money for bail, but Dromio returned with none; then, he ran into Adriana, Luciana, and Pinch, and Pinch tied him up and put him in a “dark and dankish vault at home”; Antipholus and Dromio had to gnaw through the ropes tying them, and finally came running here to the Duke for justice.
Antipholus’ version of the events shows his perspective on all the mixed-up events and coincidences of the day, highlighting the importance of the exchange of the gold necklace and of his bail money.
Angelo says that Antipholus was indeed locked out from dinner, but insists that he gave Antipholus the chain. The merchant says that Antipholus even admitted to having the chain and was ready to duel him before he fled to the abbey. Antipholus says he has never been in the abbey, and denies all that the merchant says.
Different characters all have different versions of the day’s events. The escalating series of errors and mistakes that has been building throughout the play is reaching its peak.
The Duke asks what Dromio thinks has happened. Dromio says that Antipholus dined not at home but with the courtesan. The courtesan agrees and says that he then stole her ring. The Duke calls for the abbess, and says he thinks everyone is “stark mad.” Aegeon interrupts to say that he sees someone who will surely pay his fine: he sees Antipholus and Dromio of Ephesus but thinks they are his son and his son's servant. They, of course, don’t recognize him.
Aegeon thinks that his appearance has changed in the seven years since he has seen his son and bemoans the passage of time. He tells Antipholus that he is his father, but Antipholus says he has never seen his father and his never been to Syracuse. The Duke says that it is true Antipholus has never gone to Syracuse and thinks that Aegeon is senile.
Aegeon correctly identifies his son, but Antipholus needs both to identify as Aegeon’s son himself and to be recognized by others as such in order for him to truly adopt this identity.
The abbess enters with Antipholus and Dromio of Syracuse, much to everyone’s confusion. The Duke thinks that they must be spirits, not the real Antipholus and Dromio. Antipholus and Dromio of Syracuse recognize Aegeon. The abbess calls Aegeon her husband and identifies herself as Aemilia, his long lost wife. She explains that after the shipwreck, Corinthian fishermen took Antipholus and Dromio of Ephesus from her and left her with people from Epidamnum. She then became an abbess.
The series of errors and mistaken identities reaches its climax as both sets of twins are finally on stage at the same time. The Duke quickly resorts to a supernatural explanation for this strange occurrence. Aemilia finally reveals her true identity, and begins to unravel the tangled mess of mistakes that has driven the plot of this comedy.
The Duke begins to understand what has happened, and Adriana asks whom she dined with earlier. Antipholus of Syracuse tells Luciana that, now that she knows he is not her brother-in-law, he would like to pursue her love. Angelo sees his chain on Antipholus of Syracuse, and Antipholus of Syracuse also produces the bail money that Adriana had meant to send to Antipholus of Ephesus.
The resolution of the comedy of errors involves both the establishment of people’s true identities and the return of important objects to their rightful owners.
Antipholus of Ephesus says he will use the bail money to pay Aegeon’s fine, but the Duke says that he will simply pardon Aegeon. Antipholus of Ephesus returns the courtesan’s diamond ring to her. Aemilia suggests that everyone goes into the priory so they can “hear at large discoursed all our fortunes,” and sort everything out. Dromio of Syracuse asks if he should get his master’s things from the boat, but mistakenly addresses Antipholus of Ephesus.
Antipholus of Ephesus values the life of his father over his money. Aegeon and Aemilia’s family has finally been reunited, and the courtesan is reunited with her valuable diamond ring.
Everyone but Dromio of Ephesus and Dromio of Syracuse leaves to go into the abbey. Dromio of Syracuse says that there is a “fat friend” at Antipholus of Ephesus’ house that claimed him as her husband, but will now be his sister-in-law. They leave to go into the abbey with everyone else, and Dromio of Ephesus speaks the play’s final lines: “We came into the world like brother and brother: / And now let’s go hand in hand, not one before another.”
Now that the mistakes and coincidences of the play have been explained, the valuable objects have been given to their rightful owners, and the various marriages and romantic relationships have been sorted out, the two identical Dromios leave the stage hand in hand as brothers, highlighting the importance of familial bonds at the conclusion of the comedy.