The Duke tells Othello that he can make what arrangements he likes. The important thing is that he must leave this very night because "th' affair calls [for] haste" (277). Desdemona is somewhat taken aback by this order. But notice the Moor's reply: He loves her "with all [his] heart" (279). Truly, as the Duke notes to Brabantio, Othello "is far more fair than black" (291). Immediately, there remains only for the Moor to leave some trusted officer behind, one who will see that Desdemona is brought to Cyprus safely. Tragically, Othello chooses the very man whom he can trust least in all the world — "honest Iago" (295).
Brabantio is crushed; he is a defeated man who realizes that the Moor neither stole nor bewitched his daughter. However, he will never understand how his "jewel" (195) renounced all his paternal guidance and secretly married a man of a different race and nation. He leaves with a parting warning to Othello: "Look to her, Moor, have a quick eye to see: / She has deceiv'd her father, may do thee." (292–293). These last words to Othello in this scene are important. They are packed with irony and provide, in part, an example of dramatic presaging. Desdemona does not deceive Othello, but before long Othello will be so convinced that she has deceived him that he will murder her. Othello's reply to Brabantio is likewise ironic: He vows, "my life upon her faith!" (295). Shortly, he will take his own life because of his lack of faith in her faith — in her innocent, chaste fidelity.
In a soliloquy that ends the act, Iago introduces a second motive for his hatred of Othello; he says that it is common gossip that the Moor "'twixt my sheets . . . [has] done my office" (393–394) and, for Iago, "mere suspicion . . . will do . . . for surety" (395–396). It need hardly be pointed out here that we are listening to a man whose mind is poisoned. There is not the slightest bit of evidence anywhere in this play to indicate that Othello has had an affair with Emilia. Iago also reveals his next malicious plan of action. Aware that Othello trusts him, he will convince the Moor that Cassio is "too familiar" (402) with Desdemona. Othello, he says, "is of a free and open nature" (405); precisely, in Iago's words, Othello is an "ass" — naive, in other words, and we recall that Othello himself has already admitted that he knows "little of this great world . . . [except that which] pertains to feats of broils and battle" (86–87). In the final couplet, which contains the reference to "hell and night" (409) and to "monstrous birth" (410), we sense Iago rubbing his hands in glee; we see all too clearly the unnaturalness and the diabolical elements of his plans to destroy the union of Othello and Desdemona.
