Othello puts Cassio in charge of the guard that night. He will watch over the city as they celebrate. Othello leaves with Desdemona to spend their first night together.
Cassio and Iago are left on watch together. Cassio is ready to get to work, while Iago is hoping to get him drunk. Iago convinces him that Othello has asked him to start working too early. They still have some time to enjoy wine with their friends. Unknown to Cassio is the fact that Iago has already been at work getting three other honorable men drunk. They are the friends who are coming to drink with them.
Before long, all the men but for Iago are drunk. Montano is there with them too. They bask in merriment and song. At one point, Cassio tries to convince the others that he isn’t drunk; however, he isn’t very convincing. Eventually, Cassio and his men leave to stand watch. Iago, alone with Montano, convinces Montano that Cassio drinks daily and is quite the foolish drunk. Iago can’t believe that Othello gave Cassio such responsibility as a lieutenant.
Offstage there’s a commotion. Then, Roderigo runs in with Cassio at his heels. Cassio threatens Roderigo for trying to “teach him his duty.” Before they’re able to fight, Montano tries to restrain Cassio. Cassio is able to get out of his hold and he begins to fight Montano. Roderigo goes out to stir up the rest of the town by ringing the town’s bell. Meanwhile, Iago gets the other drunks to try to help. There is quite a commotion until Othello comes around. He gets everybody to stop. Luckily, Montano was the only one who was injured during the crazy scene.
Othello is in an uproar. He tells his men to go stop whoever is ringing the bell. Then, he asks who started the fight. Iago tells him that he isn’t sure who started it. One minute they were friendly towards each other and then the next minute, they were sword fighting. Othello chastises Cassio for not knowing better. He also chastises Montano for risking his reputation over a silly fight. Montano remarks that he was simply defending himself. Montano is too injured to say much more.
Iago confesses that he does know what happened. He describes the scene to Othello and then Othello makes his judgment. Othello believes that Iago is very honest and he probably recounted the events in a way that casted a favorable light on his friend Cassio. However, Othello must punish Cassio. He decides to strip Cassio of his position.
Everybody but for Cassio and Iago leave. Cassio is super upset at himself for his actions. He cannot believe that he has just destroyed his own reputation. Iago, slyly, asks if Cassio remembers who it was that got him so upset. Cassio doesn’t recall. Next, Iago convinces Cassio to try to get Desdemona to speak on his behalf. Maybe, Desdemona can convince Othello to give Cassio back his position. Cassio likes the idea.
Left alone, Iago remarks on how Desdemona will soon be talking to Othello on Cassio’s behalf. Iago plans to convince Othello that Desdemona has a crush on Cassio; so, when Desdemona begins to speak fondly about Cassio, Othello will begin to have his suspicions. Iago wants to turn Othello against Desdemona and Cassio.
Roderigo enters the scene. He whines to Iago on how he’s nearly out of cash and how he’s been cudgeled (beat with a club). Iago encourages him to be patient. They then leave for bed.