Othello is completely overwhelmed by the thought of Desdemona’s sexual promiscuity, her infidelity with his lieutenant, Michael Cassio so much that he collapses in a stupor. We note the switch to prose and his use of short exclamatory sentences during his ‘imaginings’.
Meanwhile, Iago lies, statins that Cassio was present during Othello’s trance – that he was being mocked.
Iago questions Cassio about Biance, suggesting to Othello – who has been ordered by Iago to retreat out of sight deliberately to overhear the forthcoming conversation – that the discussion about sexual liasons and conquests are related to Desdemona – not Bianca. Othello witnesses Bianca’s arrival with the handkerchief.
All of this presents the “ocular proof” so desired by Othello.
Othello’s first utterance after Cassio and Bianca leave the scene concerns the murder of Cassio, but his love for Desdemona remains obvious and has not been completely extinguished; Iago must continue to refute Desdemona in fear that the Moor may change his mind, and we are reminded of Iago’s soliloquies and that Cassio is not the only reputation (or life) he wishes to destroy.
Desdemona’s positive attributes are constantly on Othello’s mind, as he vacillates between letting her live and her death. But Iago’s ridicule – that Othello accepts being a cuckold and therefore will have his reputation and male pride tarnished – seals Desdemona’s fate – even suggesting that strangulation, as opposed to “poison”, will have greater significane should it be performed upon their bed.
Lodovico’s arrival signals a change in the command at Cyprus, and when Desdemona reacts pleasantly to the news that Cassio will assume Othello’s position, the Moor becomes enraged, slapping her in front of the assembled. Iago, ever “honest”, admits to a contrast in behaviours exhibited by Othello but offers no reason, merely suggesting that Lodovico should continue to pay attention to future events.