Iago continues preying on Othello, pretending to give Desdemona the benefit of the doubt. He's got Othello begging for each word about what Iago knows from Cassio. Othello has a mini-breakdown, babbling, "Pish! Noses, ears, and lips. Is't possible? Confess? Handkerchief? O devil!" (IV.i.42-43). He falls into a trance and Iago rejoices in his evil effects. Cassio enters and Iago tells him that Othello is in an epileptic fit. Iago revives Othello, but telling him to "be a man" (IV.i.65); after all, the world is full of cuckolds. He will talk with Cassio in a way that Othello can secretly witness.
Iago talks with Cassio sufficiently out of earshot about Bianca so that by the laughter and bawdry Othello can think they're discussing Cassio's affair with Desdemona. Othello then catches a glimpse of the handkerchief when Bianca pitches a fit at Cassio over the token.
At Iago's instigation, Cassio runs after Bianca, giving Iago time to rub in what apparently was being discussed, and Othello is homicidal. He praises Desdemona, but with a nostalgic brokenheartedness. Iago recommends strangling Desdemona in the bed she contaminated (IV.i.207-208).
Lodovico arrives from Venice with another summons for Othello. He is sorry to learn from Desdemona that there's been the falling out between Othello and Cassio. He soon witnesses Othello violent with Desdemona and generally losing it: "You are welcome, sir, to Cyprus.--Goats and monkeys!" (IV.i.263). The apparent non-sequitur unleashes the imagery of bestiality and carnality. Iago implies to Lodovico that Othello is a big disappointment, to which Lodovico states, "I am sorry that I am deceiv'd in him" (282).
Othello grills Emilia about Desdemona and Cassio. Emilia insists to Othello that Desdemona is faithful, but Othello is past trusting women. He rails at a baffled Desdemona, ultimately calling her a whore. When he leaves, Emilia brings Iago to Desdemona, but he feigns ignorance. Emilia senses that "some eternal villain, / Some busy and insinuating rogue, / Some cogging, cozening slave" devised the slander (IV.ii.130-133). She tends to serve as a safety valve for the audience's feelings in this scene (Goddard, II 97). Iago can only suggest feebly that "The business of the state does him offense, / And he does chide with you" (IV.ii.166-167).
The women go to supper. Roderigo enters, accusing Iago of pilching the jewels intended as gifts for Desdemona. Iago admits it's been slow going, but he flatters Roderigo by playing up his newfound gumption here. If Desdemona isn't his two nights from now, Roderigo can kill Iago treacherously. Iago tells him that Othello has been summoned by Venice, but he and Desdemona would have to stay in Cyprus if there were "some accident" such as the "removing of Cassio" (IV.ii.226-227), er, um, like "making him uncapable of Othello's place: knocking out his brains" (IV.ii.229-230). So Iago convinces Roderigo to ambush Cassio tonight in the midnight hour. Iago will back him up, just in case. They exit, with Iago promising to explain fully the various reasons they need to kill Cassio.
Othello and Lodovico go out for a walk while Emilia helps Desdemona prepare for bed. Desdemona seems to have some premonition about what's coming, and she reminisces about her mother's maid singing the melancholy song "Willow." Is there a meditative punning on "Will O" (Ogburn and Ogburn 519)?
Desdemona asks Emilia if "there be women do abuse their husbands / In such gross kind" (IV.iii.62-63). She asks if Emilia would be unfaithful "for all the world" (IV.iii.64), and Emilia thinks that might be a good deal. Emilia then offers the following:
I do think it is their husbands' faultsThis speech appears only in the Folio text and therefore seems a late addition or afterthought. Is it relevant to the play?