Othello Act 3 Scenes 3 and 4, Act 4 Scenes 1, 2 and 3, and Act 5 Scenes 1 and 2

In Act 3 Scene 3 Desdemona wants to give Cassio another chance and reassures him that Othello won't be angry with him: "Do not doubt, Cassio, but I will have my lord and you again as friendly as you were." (III.iii.4-7). Othello and Iago enter and Cassio leaves because he is uncomfortable: "I am very ill at ease, unfit for mine own purposes." (III.iii.32-33). Desdemona tells Othello that Cassio feels bad about what happened and Othello should talk to him: "I' sooth so humbled that he hath left part of his grief with me to suffer with him. Good love, call him back." (III.iii. 52-54). Iago and Othello are then left alone and Iago starts to ask questions about Cassio. Othello becomes suspicious: "Nay, yet there's more in this? I prithee speak to me as to thy thinkings, as thou dost ruminate, and give thy worst of thoughts the worst of words." (III.iii. 130-134). Iago tells Othello to watch Desdemona: "Look to your wife; observe her well with Cassio." (III.iii.197). Othello begins to think that Desdemona is cheating on him: "She's gone. I am abused, and my relief must be to loathe her." (III.iii.266-267). Othello and Desdemona leave for dinner and Desdemona drops her special handkerchief. Emilia gives it to Iago who plans on using it to frame Desdemona: "I will in Cassio's lodging lose this napkin and let him find it." (III.iii.318-319). Iago tells Othello that he saw Cassio with Desdemona's napkin and Othello wants Cassio dead: "Within these three days let me hear thee say that Cassio's not alive." (III.iii.469-470).
In Act 3 Scene 4 Desdemona and Othello meet up. Othello asks Desdemona for her napkin but she obviously does not have it. He keeps bugging her about where it is and she keeps avoiding the question. She even changes the subject at one point: "Why, so I can; but I will not now. This is a trick to put me from my suit: pray you let Cassio be received again." (III.iv.87-89). Othello gets angry and leaves. Everyone wonders why Othello is angry so Iago goes to talk to him. Meanwhile, Bianca enters and Cassio asks her to make a copy of Desdemona's napkin: "I know not neither, I found it in my chamber. I like the work well. Ere it be demanded, as like enough it will, I would have it copied." (III.iv.187-189).
In Act 4 Scene 1 Iago and Othello have a conversation about Desdemona and Cassio. Iago tells Othello that Desdemona and Cassio were in bed together: "With her, on her; what you will." (IV.i.35). Cassio arrives and Othello hides while Cassio and Iago talk about Bianca. Cassio claims he doesn't love her and Bianca angrily storms in with Desdemona's handkerchief. With this, Othello is certain she is cheating on him. Othello plans to kill Desdemona: "Do it not with poison. Strangle her in her bed, even the bed she hath contaminated." (IV.i.209-210). Iago offers to kill Cassio: "And for Cassio, let me be his undertaker." (IV.i.213). Lodovico and Desdemona enter. Othello shows his anger towards Desdemona and hits her. Lodovico is astonished by this.
In Act 4 Scene 2 Othello and Emilia discuss Desdemona. Emilia says that Desdemona is a good person and whoever says otherwise is evil: "If any wretch have put this in your head, let heaven requite it with the serpent's curse, for if she be not honest, chaste, and true, there's no man happy." (IV.ii.15-18). This is ironic because it was her own hsband who said this about Desdemona. Desdemona and Othello speak of Desdemona's infidelity and she has no idea of what he is accusing her of: "By heaven, you do me wrong!" (IV.ii.80). Iago comes in, acting like he has no idea what is going on and why Othello said what he said: :Beshrew him for 't! How comes this trick upon him?" (IV.ii.128-129). Iago convinces Roderigo to kill Cassio in exchange for Desdemona.
Nothing much happens in Act 4 Scene 3, but in Act 5 Scene 1 Roderigo attempts to kill Cassio. Roderigo is killed by Iago and Cassio is wounded.
In Act 5 Scene 2 Othello smothers Desdemona and he admits it: "She's like a liar gone to burning hell. 'Twas I that killed her." (V.ii.128-129). Iago kills Emilia after she tells Othello the truth about the handkerchief. Othello chases down Iago and stabs him and later stabs himself. Before he dies, Othello kisses Desdemona, knowing he falsely accused her.
After reading this entire play, I definitely blame Iago, but everyone had the chance to ignore him and move on with their lives. If Othello didn't listen to the rumors that Iago told him, he wouldn't have killed his wife and ultimately himself. Even if the rumors were true, he could have calmly discussed the matter with his wife. He should believe his wife anyway instead of some random guy. Isn't marriage based on trust? In the end,Othello's jealousy overcame him and he handled things in the worst way possible.