i: Iago, complaining that he has been passed over for promotion, expresses to Roderigo his hatred of Othello. They wake Brabantio and reveal that his daughter, Desdemona has run off with Othello. .
I.ii: Iago complains to Othello about Roderigo. Cassio comes to get Othello for the Duke, but before they can leave, Brabantio, Roderigo, and others arrive and threaten Othello, saying that he has "enchanted" Desdemona. .
I.iii: Brabantio accuses Othello of bewitching Desdemona, but soon Desdemona testifies of her love for Othello. The Duke, satisfied, announces that Othello must leave immediately for Cyprus. Desdemona, aware that she can no longer live with her father, asks to go with her husband to Cyprus. The Duke agrees, and Othello charges Iago to bring Desdemona and Emilia on a later ship. Iago and Roderigo discuss the situation. Iago advises Roderigo to fill his purse and go with them to Cyprus so he can win Desdemona's affections.
Act II .
II.i: Cassio arrives at Cyprus, then Iago (with Desdemona and Emilia), then Othello. The Turkish fleet has been destroyed by a storm, so there is no more danger of invasion. Iago convinces Roderigo that Desdemona is having an affair with Cassio then, in a soliloquy, announces his several reasons for seeking revenge. .
II.ii: In this very short scene, a herald announces Othello's orders for a combination victory-wedding celebration. .
II.iii: Iago gets Cassio drunk, then sends Roderigo to fight him. Montano comes to Roderigo's aid and is wounded by Cassio. Othello stops the fighting and, when Iago (pretending reluctance) indicts Cassio, Othello dismisses Cassio. Cassio laments his loss of reputation, and Iago suggests that he approach Othello through Desdemona.
Act III .
III.i: Emilia agrees to arrange a meeting between Cassio and Desdemona. .
III.ii: Another very short scene. Othello sends his letters back to Venice. .
III.iii: Desdemona promises to help Cassio. When Othello arrives, Cassio leaves--and Iago takes the occasion to plant some seeds of doubt.