Egeon, a merchant from Syracuse, is spending time in the city of Ephesus. Being in Ephesus means Egeon’s life is about to get complicated. Because of some recent strife between the cities of Ephesus and Syracuse, any citizen of either locale caught in the enemy territory is sentenced to death (unless he can pay 1000 marks as a ransom for his life). The Duke of Ephesus explains all of this to Egeon as he hands him a death sentence for trespassing on Ephesian soil. Egeon is eager to get the death sentence – execution is no big deal because his life is pretty crappy – he’ll even explain why.
A long time ago, Egeon was making a lot of money as a merchant. When his agent died, he went on a business trip with his pregnant wife, who gave birth to identical twin boys while they were away from home. At the same exact time, a poor woman in the same inn also gave birth to identical twin boys. The poor woman sold her boys to Egeon to be servants for his twins. On their way home to Syracuse, a terrible storm overtook the ship that Egeon and his family were sailing in. During the storm, Egeon looked after one of his twin sons and one of the twin servants, as did his wife. However, during the storm, the boat was destroyed and the husband and wife, along with the boys, were separated. Egeon’s wife and one set of boys were rescued by a Corinthian ship, and Egeon and the two boys with him were picked up by a ship bound for Epidaurus. Thus separated, Egeon never saw his wife or lost son again.
Egeon named his set of boys after their missing twin brothers. He raised the boys until they were 18, at which point his biographical son got inquisitive about his lost brother. Egeon’s son set off with his servant to find their lost halves. Since then, Egeon has wandered around looking for them. Egeon has now lost all hope, and he welcomes the Duke’s death sentence. The Duke gives Egeon until sunset to beg or borrow the money to ransom his life.
Meanwhile, the son that Egeon raised in Syracuse has shown up in Ephesus, the very place his dad came to look for him. His name is Antipholus, and his servant’s name is Dromio (but we’ll call them S. Antipholus and S. Dromio, as they’re from Syracuse, and their initials will help us avoid confusion as the play progresses). S. Antipholus sends S. Dromio to go get them a room at a local inn called the Centaur.
Just then, Dromio of Ephesus (who we’ll call E. Dromio) happens upon S. Antipholus and mistakes the Syracusian for his master, Antipholus of Ephesus (who we’ll call E. Antipholus). E. Dromio bids S. Antipholus to come home to dinner with E. Antipholus’s wife. S. Antipholus is reasonably confused, and ends up beating E. Dromio. E. Dromio runs away.
E. Dromio goes back to his master’s house. Adriana, E. Antipholus’ wife, is angry that her husband hasn’t returned.
S. Dromio, back at the marketplace, meets up with S. Antipholus. S. Antipholus beats S. Dromio for fooling around earlier and telling him weird messages about his "wife" wanting him home for dinner. (But we know that S. Antipholus was talking with E. Dromio earlier, not S. Dromio.) Then the two men are accosted by Adriana (E. Antipholus’s wife), with Luciana (Adriana’s sister) in tow. The two women add to the confusion, and they insist S. Dromio and S. Antipholus come home to dinner with them, as they mistake the men for their Ephesian counterparts. S. Antipholus is confused, but he decides to go with the flow and follow this woman who claims to be his wife. S. Dromio is left to play the keeper of the gate at E. Antipholus’s house and allow nobody inside.
Next, we finally meet the real E. Antipholus, who’s been busy with Angelo the goldsmith, making a gold necklace for Adriana. E. Antipholus goes back to his house with E. Dromio, Angelo, and a merchant named Balthazar. The men all arrive expecting to eat dinner, but they get home to find the gate is locked. S. Dromio, who can’t see the men through the gate, is taking his gate porter duties really seriously, refusing to let them in.
The mayhem only increases, but E. Antipholus and E. Dromio eventually decide to have dinner elsewhere. E. Antipholus asks Angelo the goldsmith to bring him the gold necklace during dinner.
Meanwhile, things aren’t any prettier inside E. Antipholus’s house. S. Antipholus (who is wifeless, as far as he knows) is trying to woo Luciana, his lost-brother’s wife’s sister. (High drama.) Luciana, unsure of how to respond, deflects his offers and runs off.
The situation is getting uncomfortable, so S. Antipholus instructs S. Dromio to go find a ship, so they can get out of this bewitched city. Before he leaves Adriana’s house, S. Antipholus is stopped by Angelo the goldsmith. Angelo mistakes S. Antipholus for E. Antipholus, and gives him the golden necklace and refuses payment, saying he knows he’ll get paid later. S. Antipholus wants to get out of this place ASAP, but doesn’t mind taking such a nice gift.
Later in the day at the marketplace, Angelo the goldsmith sees E. Antipholus and approaches his client for payment for the necklace. E. Antipholus, as he never received the necklace, says Angelo must be talking madness. Poor E. Antipholus gets arrested for avoiding paying his debt.
The wrongly imprisoned E. Antipholus is furious. S. Dromio approaches and tells E. Antipholus he’s secured the ship that S. Antipholus asked for. Since E. Antipholus didn’t ask for a ship, he figures Dromio is crazy, too. Wanting to be freed from jail, he sends S. Dromio to Adriana to get bail money. When S. Dromio reaches Adriana and tells her what happened, Adriana sends the servant off with bail money.
S. Dromio, rushing back to the marketplace to bail out E. Antipholus, runs into S. Antipholus. S. Dromio tries to give his real master the bail money, but S. Antipholus is confused, and just asks about the ship he sent S. Dromio for a long time ago.
E. Antipholus, still arrested, is met by E. Dromio, who knows nothing of his master’s arrest. The servant was just receiving a beating when Adriana, Luciana, and a schoolmaster named Pinch arrive. Adriana, thinking her husband is possessed, begs the schoolmaster (who is apparently a part-time exorcist) to cure her husband of whatever demon has possessed him. E. Antipholus is angry and tries to attack Adriana. Ultimately, E. Antipholus and E. Dromio are tied up, and taken to Adriana’s house.
After the men have been taken away, the women try to clear up E. Antipholus’s debt (and figure out its origin) with the arresting officer. As they’re puzzling it out, they’re encountered by S. Antipholus and S. Dromio. The Syracusians mistake Adriana and company for witches, and run at them with swords drawn. Everyone scampers off.
Angelo the goldsmith shows up again and sees that S. Antipholus is wearing the necklace that E. Antipholus denied receiving. S. Antipholus says he never denied anything. The squabble is getting tense and the men are ready to duke it out. Adriana and Co. enter just as the men are about to fight. S. Antipholus and S. Dromio take the opportunity to slip into a conveniently located priory (or religious place) nearby.
The Abbess (a religious lady of the priory) comes out, and asks exactly what all the fuss is about. Adriana begs the Abbess release her husband, but the Abbess refuses, as it would violate their sanctuary in the priory.
Just then, the Duke shows up on a merry jaunt to have Egeon beheaded. Adriana wants the Duke to make the Abbess release her husband, but her request is interrupted by a messenger. The messenger says that E. Antipholus and E. Dromio have escaped their bonds, singed Pinch’s beard, and are now headed towards the priory to rage against Adriana and Co.
Just then, E. Antipholus arrives and pleads for the Duke to deliver justice against his wife, who has much abused him. The Duke throws his hands up and declares everyone is insane. To add to the craziness, Egeon takes this moment to pipe up that he recognizes Antipholus is the son he raised in Syracuse. Of course, E. Antipholus says he’s never seen his father in all his life, causing Egeon to despair.
This fine kettle of fish is FINALLY de-fishified when the Abbess re-enters the scene with S. Antipholus and S. Dromio in tow. Everyone sees the four men, in two identical sets, face to face. Then they realize what’s been going on the whole time. S. Antipholus recognizes his dad, and the Abbess reveals that she’s actually Aemilia, Egeon’s long lost wife. S. Antipholus takes the opportunity to reiterate his offer of marriage to Luciana. The Duke even frees Egeon! Instead of death and disorder, the play ends with the Abbess calling everybody into the abbey, so they can share the stories of their lives since their separation.