The scene opens with Desdemona talking to Cassio; she is reassuring him that she will do everything she can to repair his reputation in Othello's eyes. She, like others before her, calls Iago an "honest fellow." She assures Cassio that she will make every moment of Othello's life all about Cassio.
Othello and Iago enter, which makes Cassio nervous. He insists on leaving. Even though Desdemona tries to encourage him to stay, he cannot make himself do it. When Iago sees Cassio rushing off, he cleverly initiates the process of planting doubt into Othello's mind. When Othello asks if that was Cassio leaving, Iago says he can't imagine why Cassio would be stealing away in such a guilty fashion.
Desdemona greets Othello and tells him she was just visiting with someone, namely Cassio......
