Othello leaves Cassio on guard during the revels, reminding him to practice self-restraint during the celebration. Othello and Desdemona leave to consummate their marriage. Once Othello is gone, Iago enters and joins Cassio on guard. He tells Cassio that he suspects Desdemona to be a temptress, but Cassio maintains that she is modest. Then, despite Cassio’s protestations, Iago persuades Cassio to take a drink and to invite some revelers to join them.
Once Cassio leaves to fetch the revelers, Iago tells the audience his plan: Roderigo and three other Cypriots, all of whom are drunk, will join Iago and Cassio on guard duty. Amidst all the drunkards, Iago will lead Cassio into committing an action that will disgrace him. Cassio returns, already