Montano and two gentlemen are on the lookout, expressing their fears with respect to the tempest at sea, of the shipwrecks and disasters that such a storm is liable to cause, when news arrive: The storms have rendered the Turkish Fleet inoperative, and a Venetian ship, conveying Michael Cassio, has safely anchored at port. Montano and the gentlemen go to greet Cassio.
Though the Venetians have gotten the better of the Turks, Cassio is despondent on account of the storms which have scattered the Venetian fleet. A sail is descried and the hope is that Othello is on board. It turns out to be the next best thing: the ship has brought Desdemona whom Cassio greets with every honor that a gentleman can bestow a lady. (Also on board are Iago, Emilia, and Roderigo.) Though pleased with Cassio’s gallantry, Desdemona is inwardly distressed at Othello’s absence. She bides her time by censuring Iago’s barroom humor that leaves no stone unturned with respect to disparaging women, not the least of whom Emilia, his own wife. Suddenly a sail is descried. It is Othello! Thus united, Desdemona dotes on Othello and vice-versa. Their happiness is a fitting end to the Turkish wars.
Left alone with Roderigo, Iago reveals phase one of operation Undermine Othello’s Happiness. Roderigo is to cause Cassio to lose his lieutenancy by provoking him into a brawl. When asked what purpose this would serve, Iago argues that if Cassio is allowed to just be, then he and Desdemona would, by and by, become lovers. Roderigo doubts this, but Iago bombards Roderigo with a host of ideas, among them a woman’s susceptibility to sensual pleasures and Cassio’s natural attractiveness to married women everywhere, not the least of whom Desdemona. Would Roderigo, who has sold all his lands (for the sake of Desdemona), come this far only to let Cassio deprive him of his prize? Roderigo reckons not.
On behalf of Othello, a herald makes a proclamation to the people of Cyprus. Reports have confirmed that the Turkish fleet has been destroyed. The war is, for intents and purposes, at an end. In light of this, and in light of Othello’s recent wedding, celebrations are to commence at this very hour (five) until eleven this evening.
Having found Iago with whom he is to supervise the evening’s guard duties, Cassio tries in vain to avoid drinking more wine. Indeed, before he knows it, Cassio finds himself drunk, thanks to Iago. Duty must be attended to, however. Directly, Cassio departs from the drinking scene where Iago remains conversing with Montano who is led to believe that Cassio is a habitual drunkard. Iago is explaining that even though he is duty-bound to make Cassio’s abuses known to Othello that he is prevented from doing so on account of the love he bears Cassio when a noisy commotion draws everyone outside. Cassio, in a drunken rage, is assaulting Roderigo who has provoked the assault as per Iago’s instructions. Montano tries to restrain Cassio only to have Cassio turn against him. A brawl ensues between Cassio and Montano. Upon Iago’s advice, Roderigo raises a dire yell while making a run for it with Iago at his heels. The clamor sets off Cyprus’ alarm bells, compelling Othello to make an appearance. The brawl is broken up and an explanation is demanded. Having returned from his mock pursuit, Iago offers one, feigning concern for Cassio whose guilty role Iago mitigates as best he can. Othello commends Iago for trying to stick up for his friend but relieves Cassio of his duties effective immediately.
Iago tries to console Cassio, but understandably Cassio is inconsolable. He has lost his reputation, after all, which if lost once is virtually irretrievable. Iago begs to differ. What is often gained or lost reputation wise, he argues, is unwarranted. Othello did what he did in a fit of anger. Petition him at a later date, when his anger has abated, and the chances are that Cassio will regain his former status. Iago pledges to help Cassio in this cause, advising Cassio to plead his case to Desdemona so that she might petition Othello on his behalf. It is a course of action that makes a lot of sense. Grateful, Cassio leaves feeling considerably better. Alone, Iago ruminates on the wisdom of his advise, of how truly beneficent it is when regarded disinterestedly. Of course, things are not what they seem.