In this act, we see the total cunningness of Iago. Iago was able to fool every character in the play by distorting reality and focus in on what appears to be the truth rather than the truth itself. Iago fools Othello in what appears to be Cassio admitting to sleeping with Desdemona when in fact a confession must be heard and not seen through facial expressions. Another interesting point is the time when Othello is called back to the city and Cassio is going to replace him in Cyprus. This can further anger Othello since Cassio is not only replacing him in his personal life but also in his job.
At the start of the play, we understand why Iago seeks revenge and harm on Othello for choosing Cassio. However, it is interesting to note that when Othello has had enough and chooses to poison his wife in bed, it is not enough for Iago. Iago says, ” Do it not with poison. Strangle her in her bed, even the bed she hath contaminated.” Iago wants Desdemona to die a harsher death. What has she ever done to him to deserve this punishment?