When Desdemona enters and Othello complains of an aching head, Desdemona offers to bind his head with her handkerchief. As they exit, the handkerchief drops unnoticed by either of them. Emilia picks it up and gives it to Iago, who has often asked for it. Othello reenters and, now tormented by jealousy, threatens Iago with death unless he provides proof of Desdemona’s infidelity. Iago alleges that Cassio one night talked in his sleep about making love to Desdemona and that Cassio once wiped his beard with the lost handkerchief. Othello is convinced by this “proof” and vows to kill Desdemona; Iago agrees to kill Cassio. Othello then appoints Iago to the lieutenancy.
In the streets of Venice, Iago tells Roderigo of his hatred for Othello, who has given Cassio the lieutenancy that Iago wanted and has made Iago a mere ensign. At Iago’s suggestion, he and Roderigo, a former suitor to Desdemona, awake Desdemona’s father to tell him that Desdemona has eloped with Othello. This news enrages Brabantio, who organizes an armed band to search for Othello.
Act 1 Scene 1
Iago warns Othello about Brabantio’s anger, but Othello is confident in his own strength and in his love for Desdemona. Cassio arrives and orders for Othello: Othello is to meet with the duke and senators of Venice about a Turkish invasion of the Venetian colony of Cyprus. Brabantio and his armed band come to seize Othello, who persuades Brabantio to accompany him to the duke, where Othello has been summoned and where Brabantio can present his case against Othello for his “theft” of Desdemona.
Act 1 Scene 2
The duke and the senators discuss the movements of the Turkish fleet and conclude that its target is, indeed, Cyprus. When Brabantio and Othello arrive, the duke insists on evidence to support the old man’s charge that Othello has bewitched Desdemona. At Othello’s suggestion, the duke sends for Desdemona. Othello describes his courtship of Desdemona, who, when she enters, tells her father and the senators that she has married Othello because she loves him. She thereby vindicates Othello before the senate. The duke orders Othello immediately to Cyprus and grants Desdemona her wish to join him there. Othello gives Iago the duty of conveying Desdemona to Cyprus. Alone with Iago, Roderigo, now in despair of winning Desdemona’s love, threatens suicide, but Iago persuades him instead to sell his lands for ready cash and to pursue Desdemona to Cyprus. Iago begins to plot to himself how he may use Othello’s marriage to get back at Othello and to get Cassio’s place as lieutenant.
Act 1 Scene 3
The Turkish fleet is destroyed in a storm while Cassio and then Desdemona, Emilia, and Iago arrive safely at Cyprus. Desdemona anxiously waits for Othello. When his ship arrives, he and Desdemona joyfully greet each other. Iago putting his plot into action, persuades Roderigo that Desdemona is in love with Cassio and that Roderigo should help get Cassio dismissed from the lieutenancy.
Act 2 Scene 1
Iago gets Cassio drunk, making it easy for Roderigo to provoke Cassio into a brawl, first with Roderigo, then with Montano, whom he wounds. Othello, called from his bed by the noise, stops the brawl and strips Cassio of his lieutenancy. Iago advises Cassio to seek Desdemona’s help in getting reinstated. The next step in Iago’s plan is to tell Othello that Desdemona supports Cassio because Cassio is her lover.
Act 2 Scene 2/3
Cassio arrives with musicians to honor Othello and Desdemona. As Iago has recommended, Cassio asks Emilia to arrange a meeting with Desdemona, even though Emilia assures him that Desdemona is already urging Othello to reinstate him.
Act 3 Scene 1
Desdemona’s interview with Cassio is cut short by the arrival of Othello. Cassio leaves hastily in order to avoid speaking with Othello. Desdemona pleads to Othello on Cassio’s behalf. When she exits, Iago says that Cassio’s avoidance of Othello is suspicious and that Cassio may not be honorable, all the while insinuating that he, Iago, knows more than he is willing to say. He warns Othello against becoming jealous of Desdemona.
Act 3 Scene 2/3
Desdemona, still actively seeking to have Cassio reinstated, is worried about the loss of her handkerchief. Her anxiety about it increases when Othello asks her for it and then sternly rebukes here when she cannot produce it. Cassio approaches her, but she must now, because of Othello’s anger, postpone her efforts on his behalf. As he waits, Bianca, his lover, appears. Cassio has found Desdemona’s handkerchief in his room (placed there by Iago) and he asks Bianca to copy the embroidery work for him.
Act 3 Scene 4
Iago continues to torment Othello with vivid descriptions of Desdemona’s alleged sexual activity until Othello blacks out. Iago then places Othello where he can hear (but not see) a conversation with Cassio about Bianca, telling Othello that the bawdy conversation is about Cassio and Desdemona. Othello’s fury grows. Lodovico arrives from Venice with orders from the duke and senators that Othello return to Venice and that Cassio be appointed in his place. Othello strikes Desdemona in Lodovico’s presence, then rudely dismisses her, and leaves in a jealous rage. Lodovico expresses his astonishment at the change in Othello.
Act 4 Scene 1