Iago that Desdemona is having an affair with Cassio. This plan occupies the final three acts of the play. He manipulates his wife Emilia, Desdemona's lady-in-waiting, into taking from Desdemona a handkerchief that Othello had given her; he then tells Othello that he had seen it in Cassio's possession. Once Othello flies into a jealous rage, Iago tells him to hide and look on while he (Iago) talks to Cassio. Iago then leads Othello to believe that a bawdy conversation about Cassio's mistress, Bianca, is in fact about Desdemona. Mad with jealousy, Othello orders Iago to kill Cassio, promising to make
Desdemona as "Othello" and out of character for Desdemona. Today, however, the purpose of the passage is sometimes viewed as a depiction of Desdemona's awareness of the way of the world, and her persistence in pursuing the exchanges as a characteristic innocent overconfidence displayed elsewhere in the play (3.3.41–83, 3.4.90ff). On 8 December 1660, Thomas Killigrew's new King's Company acted "Othello" at their Vere Street theatre, with Margaret Hughes as Desdemona – possibly the first time a professional actress appeared on a public stage in England. She played Desdemona in the performance of "Othello" seen by Samuel Pepys on 6 February