Following is a brief summary of the plot of Othello.

Exposition and Inciting Incident (Act I)

The inciting incident is the elopement of Othello and Desdemona, that actually occurs before the scene I events. This case sets off all the following disputes. Actually, in act I, we meet Iago and hear about his friendship with Roderigo and his feelings against Othello. We also meet Othello and Desdemona and hear them speak in defence of their love before the Senate, in response to Desdemona’s father’s charge that the Moor took his daughter by unlawful means. Once the charges against Brabantio have been dismissed, the Duke announces that Othello must be sent to Cyprus immediately to ward off an attack by the Turkish enemy. He grants permission to Othello to bring his bride along. At the end of the act, Iago reveals in a soliloquy how he wants to get his vengeance on Othello: he is going to “abuse Othello’s ear / That [Cassio] is too familiar with his wife.”

Rising Action (Act II)

Several weeks elapsed at the beginning of Act II and the conflict with the Turks has ended, with the Turkish fleet sunk by a storm at sea. The characters all land safely on Cyprus Island, and a party is scheduled for that evening. Iago enacts the first part of his plan during the revels of the night, by getting Cassio drunk. As the pair had arranged earlier, Roderigo picks a fight with the drunk Cassio, and a fight follows. Othello intervenes, and finds Cassio guilty, dismisses him from his position as lieutenant. Iago encourages Cassio to seek help from Desdemona to win back Othello ‘s favour.

Crisis and Climax (Act III)

In Act III the rising action continues as Cassio visits Desdemona and she promises to plead his case with Othello. Iago and Othello spot Cassio leaving and Iago suggests Cassio looks guilty to Othello. He keeps making insinuating remarks about Cassio and Desdemona, suggesting the two were intimate. When Othello asks him for evidence, Iago informs him he’s seen Desdemona’s handkerchief in the hand of Cassio. This detail pushes Othello to the breaking point and leads to the play’s crisis — a point which we can also consider to be the climax.

Othello is Completely persuaded and vows his revenge: “Now do I see
’tis true. Look here, Iago; / All my fond love thus do I blow to heaven. / ’Tis gone. / Arise, black vengeance, from thy
hollow cell!”. He tells Iago to kill Cassio then he promotes Iago to lieutenant. Now the crisis or the climax has been reached, the action is now beginning to fall to its inevitable resolution. In Act III, Scene iv, Othello questions Desdemona about the unknown handkerchief which, unbeknownst to the two of them, Emilia has stolen and given to Iago, Who placed it in the Chamber of Cassio. A disconcerted Desdemona attempts to change the subject by bringing up the case of Cassio. When she pleads for his reinstatement, Othello is ever more furious at what he sees as evidence of her love for Cassio

Falling Action (Act IV)

Iago proceeds his lies, telling Othello that Cassio admitted that Desdemona had an affair with him. He arranges for Othello to hide while he asks Cassio about Desdemona. While Othello looks, Iago asks Cassio about Bianca, a subject that provokes the laughter of Cassio.

In the meantime, Bianca comes along with Desdemona’s handkerchief, which Cassio gave her to copy. This serves as the “ocular proof” that Othello wanted — he’s now fully convinced that his wife was unfaithful, and he’s going mad with grief and a desire for revenge. The emissaries arrive from Venice at the end of Act IV, scene I, with the news that Othello is being recalled to Venice, leaving Cassio as governor of Cyprus.

When Desdemona states that she is happy about it, Othello hits her, shocked everyone. In Act IV, scene ii, Othello questions Emilia about the fidelity of Desdemona but refuses to believe that Desdemona is chaste. Later on, Iago and Roderigo were plotting the murder of Cassio. In Scene Iii, Desdemona waits for Othello in her bedroom, and as Emilia helps her prepare for bed, the women talk about infidelity.

Desdemona declares that she would never cheat on Othello for “all the world.” This knowledge, in the eyes of the audience, makes her impending death all the more tragic.

Resolution and Denouement (Act V)

The falling action continues throughout act V. In scene I, Roderigo and Iago fail in their attempt to murder Cassio. Roderigo and Cassio are both wounded, and Iago kills Roderigo to cover up for his role in the attack.

In the second scene, Othello enters the bedroom to kill Desdemona. When she realizes what he’s going to do, she begs for mercy, but he smothers her. Emilia comes in and discovers the murder, where Othello tells her that Desdemona was unfaithful and that Iago knew the whole story. Emilia, stunned, says, “My husband! “She is calling for help, and Montano, Gratiano, Iago, and the others are coming in. Emilia accuses her husband of committing the murder of Desdemona in front of everyone, and Iago stabs her in anger. Now that Iago ‘s role in the tragedy is clear, Othello stabs him (but doesn’t kill him), then he stabs himself. Othello ‘s death is a disaster, an event that resolves the central conflict and completes the tragedy.

The denouement comes in the lines of Lodovico at the end of the play, through which we learn that Gratiano will inherit all the possessions of Othello and that Cassio will supervise the villain Iago ‘s punishment and torture.