Angelo the goldsmith apologizes to the Merchant to whom he owes money. Angelo’s sorry to have made the Merchant wait, but he’s really shocked that E. Antipholus hasn’t come through. Then, to everyone’s surprise, S. Antipholus approaches, wearing Angelo’s necklace.
Angelo confronts S. Antipholus about the necklace, and S. Antipholus rightly says he never denied he had it. The Merchant gets involved, and says he heard Antipholus deny he had the necklace he now wears. Tempers get hot and the men draw their swords.
Adriana thankfully enters just in time to break up the fight. She tells the Merchant that her husband is mad, and she calls upon others present to bind up the mad men. S. Antipholus and S. Dromio, sensing their doom, run off into the priory (a religious house) and seek sanctuary.
Just then an abbess (the superior of a group of nuns) enters, and asks just what exactly everybody thinks they’re doing, disturbing God’s peace. Adriana informs the Abbess she’s just trying to get her man, who’s been strange over the last week, but seems to be particularly insane today.
The Abbess wonders what it is that has made the man mad. She asks if he’s lost money in a sea venture, or perhaps buried a friend, or fallen in love with another woman. Adriana admits it might be the last one about another woman (remember, she’s still standing with the Courtesan). The Abbess says Adriana should have been more firm about this.
Adriana insists she did nag him about it often, and the Abbess decides it was Adriana’s nagging that did the man in. The Abbess goes on for a bit, painting Adriana as a nagging shrew, and Luciana is surprised that her sister just lies down and takes it. Adriana says the Abbess’s criticisms of her are basically how she would’ve criticized herself. Regardless, she’d just like them to go into the priory and fetch her husband.
The Abbess is all, "I don’t think so." She says if the guys went into the priory for sanctuary, it’s sanctuary they’ll get. The Abbess also insists the man won’t leave her care until she tries all sorts of drugs and prayers and "wholesome syrups" on him. The Abbess is insistent, and she leaves Adriana distressed and without a man.
At Luciana’s suggestion, Adriana decides she’ll go to the Duke and weep at his feet until he has her husband forcibly removed from the Abbess’s care. The Merchant points out that it’s 5pm, so the Duke should be along soon to oversee the public beheading of a poor Syracusian merchant for showing up in Ephesus.
The Duke shows up with Egeon and some officers. He reminds the crowd that if anyone will provide the sum of 1,000 marks, Egeon’s life will be spared. Adriana doesn’t care so much about Egeon, and instead shouts out that she seeks some other justice, specifically against the tiny old nun. She explains to the Duke that her husband seems mad, and that the Abbess won’t let him out of, nor let anyone into, the priory.
A messenger arrives and claims that Antipholus and Dromio have broken their bonds and attacked the doctor who has been attending them with fire and scissors. The messenger says Antipholus promised he was coming to get his wife next. Adriana is incredulous, as she thinks her husband is actually in the priory.
But she’s wrong! Of course, just then, E. Antipholus shows up with E. Dromio. Adriana is shocked and convinced he moves about invisibly, as there’s no way to explain how he left the priory without her notice.
E. Antipholus pleads that the Duke owes him justice, especially in exchange for all the service E. Antipholus did for him in war. Egeon offers that he recognizes these men as his son and his son’s servant, Dromio, but the old man is ignored. Egeon’s claims are drowned out by E. Antipholus railing against his wife for abusing and dishonoring him.
The Duke then gets the whole story from E. Antipholus’s perspective: E. Antipholus complains that his wife locked him out of the house and that Angelo wrongly accused him of taking the golden necklace. Then he was wrongly arrested, and his servant, Dromio, didn’t bring his bail. When he finally got fed up and went with the officer to collect the bail from his house, he found his wife with a quack doctor, who declared him possessed and left him tied up and sealed in a dark vault in his own home. He gnawed open his bonds with his own teeth, and escaped to see the Duke. It’s been quite a day.
All this would be reason to feel really bad for E. Antipholus, but Angelo points out that he actually did give E. Antipholus the necklace, and the man was seen wearing it. The Merchant asks whether E. Antipholus doesn’t remember being challenged to a duel and running into the priory (from which it seems he’s magically escaped). Of course, E. Antipholus has no idea about any of this; S. Antipholus is still locked in the priory, and frankly this whole situation is getting a bit tiresome.
The Duke squabbles around about the Courtesan’s ring, and finally he decides everyone is mad, and someone should call the Abbess.
Egeon finally speaks up, saying he thinks he’s found men to pay his bond. He identifies Antipholus and Dromio correctly, but they have no idea who he is. He laments that he must appear much changed by grief, and then gives a beautiful speech about the passage of time. Though his face is grizzled and wrinkled, and he hasn’t aged gracefully, he says his memory still glimmers – he recognizes in this man his son, Antipholus.
Antipholus of Ephesus, seemingly unmoved, offers that he’s never seen his dad in his whole life. Egeon is insistent, he says it’s only been seven years since the men parted in Syracuse. He wonders if his son is ashamed to acknowledge him because of his miserable state.
Everyone else is incredulous. E. Antipholus insists he’s never even been to Syracuse and the Duke also asserts that he’s known E. Antipholus for twenty years, and the young man has never been to Syracuse in all that time. Egeon is about to be dismissed as a doddering old man when the Abbess enters.
Actually, not only has the Abbess come, she’s brought with her Antipholus of Syracuse and Dromio of Syracuse. FINALLY, everyone is face to face with the two sets of identical twins.
After a bit of fussing, the Abbess explains everything. First, she’s like, "Hey! That’s my man!" Then she reveals that, actually, she’s Aemilia, Egeon’s long lost wife. After the shipwreck, her boys (one son and one servant) were taken from her by some Corinthian fisherman, leaving her alone in Epidamium. She doesn’t know what happened to them from there, but it’s been her lot to live as a nun ever since.
The Duke finally takes off his Captain Oblivious cloak and hat. He declares, "These two identical sets of twins are all long lost brothers, the Antipholuses are sons of Egeon and Aemilia, and the Dromios are the two servant boys!"
Also, the boys who should’ve been in Corinth with the fisherman explain that they came to Ephesus with the warrior Duke Menaphon, who is somebody’s uncle. So that explains that. Moving briskly along, the pairs then clear up the calamity about who had dinner with Adriana, who got the necklace, who was sent for bail money, and who brought bail money.
E. Antipholus tries to pay the Duke bail for his father, but the Duke demurs, and instead just grants Egeon his life. The Courtesan gets her ring back; Egeon gets his sons back; and Aemilia gets her husband back. Also, now that it’s clear that he isn’t Adriana’s husband, S. Antipholus reiterates his offer to Luciana to be her husband and give her happiness.
Finally, Aemilia ushers everyone into the abbey so they can talk over that bad, fateful day when they were separated, and the fateful day that’s brought them together again.