Residents of Syracuse and Ephesus are not permitted to visit one another’s city. Egeon, however, a merchant from Syracuse, has disobeyed this rule and travels to Ephesus because he is looking for his wife, his older twin son, and a servant, all lost in a shipwreck. The Duke of Ephesus pities Egeon, but insists he cannot bend the law; the Syracusean must raise ransom money or be executed.
Antipholus and Dromio of Syracuse, raised by Egeon, also arrive in Ephesus looking for their shipwrecked twin brothers. Shortly after Antipholus sends Dromio to make reservations at an inn, Dromio of Ephesus arrives to bring his master to dinner and is sent away in confusion. He returns to Antipholus of Ephesus’s house and recounts to Adriana, Antipholus’ wife, and Luciana, her sister, his odd conversation with the man he thought was his master. Adriana leaves to fetch her husband and manages to convince this Antipholus that he is her husband despite his confusion; they go home for dinner.
Meanwhile, Antipholus of Ephesus, late for dinner, is walking home with Angelo, a goldsmith who has promised him an ornate necklace. When they reach his house, they find it locked. Adriana, Luciana, Dromio, and the other servants refuse to unlock the door, believing him to be an imposter since Antipholus of Syracuse is dining with them. Antipholus, angry, leaves to dine with a courtesan and asks Angelo to bring the necklace there.
While dining, Antipholus of Syracuse falls in love with Luciana, who insists that he is married to her sister. Meanwhile, a kitchen girl who Dromio of Syracuse instantly finds unattractive has claimed they are engaged. The two leave, and Antipholus sends Dromio to make plans for them to leave Ephesus.
The Syracusean also runs into Angelo and accepts the ornate necklace without payment. Later that day, however, Angelo requests his payment from Antipholus of Ephesus who insists he never received the necklace. He refuses to pay Angelo, so the merchant has Antipholus arrested. Antipholus sends Dromio of Syracuse to Adriana to collect bail money.
Adriana is quick to send money to her arrested husband, but her Dromio finds Antipholus of Syracuse, who is only interested in leaving town. The courtesan arrives to demand either the ring Antipholus of Ephesus took from her at dinner that afternoon or the gold necklace. Antipholus and Dromio believe she is a witch and flee.
Meanwhile, Adriana and Luciana employ Doctor Pinch to examine Antipholus of Ephesus, believing he is insane. Pinch has Antipholus and his servant bound and carried away, but onlookers think they have escaped when they see the Syracusian pair, fleeing the courtesan with their swords drawn.
When the merchant finds Antipholus of Syracuse wearing the gold necklace, they prepare for a duel but are interrupted when Adriana tries to force the Syracusians to go back to Pinch. They escape to the abbey, where the Abbess scolds Adriana and refuses to turn the men over to her. The Duke and Egeon pass the abbey, and Adriana stops them to beg the Duke to force the removal of Antipholus and Dromio (of Syracuse). The Duke agrees to hear the case just in time for a messenger to report that Antipholus and Dromio (of Ephesus) are on their way to the abbey.
Egeon recognizes his son and servant, but they insist they do not know him. The Abbess brings the second pair to the Duke, and everyone realizes the confusion was caused by lost identical twins. Egeon also recognizes the Abbess as Aemilia, his wife, who had been separated both from him and from her son. The Duke frees Egeon and everyone gathers for a celebratory feast.
Next: Identity in Ephesus