2) Iago expressed his hatred towards Othello because Othello chose the inexperienced Cassio as his lieutenant instead of him. The only reason Iago still followed Othello was for him to take revenge on Othello. In order to stay in Othello's grace Iago had to pretend and swear fake loyalty to the Moor which was proven from Iago's words, "I am not what I am".
3) Iago told Roderigo to go to Desdemona's house and reported her secret marriage to her father.
4) Both Roderigo and Iago started shouting outside of Desdemona's house and rudely woke her father, Brabantio. Iago tried to raise Brabantio's anger by throwing insults at him and hinting that his daughter have done something humiliating.
5) The angered Brabantio believed Iago's and Roderigo's accusation and call for his men to check on Desdemona.
6) At the same time, Iago parted with Roderigo because he must quickly went back to Othello to play his role as the loyal assistant.
7) After he found out that Desdemona had indeed run away, Brabantio felt deceived and disbelieved of the treason his daughter had done. Brabantio ask for more men and to call for his brother to apprehend Othello.
End of Summary. Happy analyzing
