Othello Act 4, scene 1

Iago With the soliloquys and the actions of the plot, it is obvious that Iago’s hatred of Othello is all consuming. His plan is unfolding quickly, and the characters involved will begin to be affected by the lies.
Othello He can best be described as distraught. He is obsessed with the idea that Desdemona has been unfaithful. He has a “fit” (perhaps an epileptic seizure) which could be viewed as another “dig” about being an outsider–the Moor from Africa (black).
Cassio Believes Iago’s lies and views Iago as a loyal friend. He is unaware of the deception that is going on behind the scenes.
Lodovico Desdemona’s cousin from Venice, who brings word that Othello must return to Venice. He witnesses Othello’s slap to Desdemona. He believes that Othello has “gone mad”.
Desdemona She acts like the obedient wife. She does not understand the change in Othello–and his suggestions that she has been untrue. Othello will slap her in the face, and she is truly confused by his actions.
Bianca She is a “girlfriend” of Cassio. He sees her when he needs the company of a woman. She is very much in love with Cassio. He does not give her a second thought.
The Fit/Seizure Othello’s thoughts are so consumed with the thoughts and visions in his mind of Cassio and Desdemona being together that he seems to have a seizure, where he is not in his right mind. Iago delights in this, and he takes this opportunity to meet with Cassio to set another “chance” meeting.
Relationship of Iago and Cassio Iago has accomplished his mission of planting suspicions in Othello’s mind. When Othello has his “fit”, Cassio appears. Iago tells him to meet him later, and he will speak with Othello to “smooth things over” and let Cassio know the outcome of his persuasions. Cassio meets Iago, and Iago has arranged to have Othello watch the meeting from a distance. Iago talks to Cassio about Bianca, how she is so in love with Cassio. Cassio responds and laughs about this, making comments about how silly she is in thinking he loves her. Othello misinterprets what is heard and Cassio’s body language and presumes he is speaking of Desdemona.