The gold chain incident is one of the most hilarious incidents in the play Comedy of Errors by William Shakespeare. It is a result of mistaken identity and leads to the complication of the plot.
As Antipholus Younger and Dromio Younger escaped from the troubles of the house, they happened to meet a goldsmith. The goldsmith showed his acquaintance with Antipholus and gave him a gold chain. Antipholus Younger tried to make him understand that he was not the man the goldsmith was looking for. But the goldsmith mistaking younger Antipholus as Antipholus of Ephesus said that he had ordered him to make the chain. Thus Antipholus younger was forced to accept the chain. In the meantime, the goldsmith was arrested for not paying some money that he owed. He found elder Antipholus passing by his way and asked for the money. But this Antipholus demanded (justly) that he did not get the delivery of the chain. So both were arrested.
Now younger Antipholus met a lady who called him by his name and asked for the gold chain that he had promised to give her. But younger Antipholus denied having known this lady. The lady being angry asked Antipholus to give back her ring. Antipholus Younger was totally perplexed and fled from the place. This lady also mistook him as his elder brother.
Actually, elder Antipholus wanted to avenge his wife for not admitting him into the house the other night. He had ordered the goldsmith a chain for his wife. But after being denied admittance into the house he dined with this lady and promised to give her the chain. This lady, being pleased, gave elder Antipholus a ring which she was now demanding from younger Antipholus. The lady thought that Antipholus had gone mad and resolved to report it to Adriana, the wife of elder Antipholus.