The eavesdropping scene neatly captures Lorenzo's Machiavellian dynamic. It also juxtaposes to great effect the bitterness of Lorenzo and Balthazar against the beauty of the lovers' love, and it captures the conflict between them (which right now forms the conflict of the play). The exchange of loving words between Horatio and Bel-Imperia are ironically juxtaposed against the threats of Balthazar and Lorenzo, making their poetic exchanges seem tragic. At one point, they surreptitiously participate in a stichomythia between Horatio and Bel-Imperia, inverting Horatio's sentences, ominously foreshadowing bad events for Horatio. The use of the oxymoron, "warring peace," and of a parallelism that develops an elaborate analogy between love and war also adds to the sense of paradox and irony attached to the scenes, where love and hatred seem to give birth to each other—Bel-Imperia's hatred for Balthazar gives rise to her love for Horatio, and Balthazar's love for her gives rise to his hatred for Horatio. The culmination of these ironic juxtapositions comes in the final lines of scene ii, where Horatio's remark, "dangerous suspicion waits on our delight," is, unbeknownst to him, confirmed by Lorenzo: "Ay, danger mixed with jealous despite / Shall send thy soul into eternal night," foreshadowing Horatio's eventual death.
The scene is thus rife with dramatic irony. Horatio makes arrangements for a lover's rendezvous, but Lorenzo knows (as we do) that he is in fact making arrangements for his death. Dramatic irony is a calling card of tragedy, since it helps create the mixture of necessity and free choice essential to the tragic mindset. That Horatio will be in his father's bower tonight is an expression of his free will and his love for Bel-Imperia. That he will meet his doom there is a product of forces beyond his control: the jealousy and hatred of Balthazar and Lorenzo. Another key irony, however, is that Bel-Imperia conceived her love, at least from one angle, as a revenge plot on Balthazar. This revenge is now about to backfire disastrously.
The juxtaposition of scene iii, in which the King and the Duke of Castile decide that Bel-Imperia should marry Balthazar, is an ironic juxtaposition. As the two old men decide Bel-Imperia's marriage, she is already rushing off into the arms of Horatio. The scene opposes Horatio and Bel-Imperia's love against the social order of the day. This makes the lovers seem more heroic, more significant, more tragic; the irony lets the audience know the social forces that are working against the young lovers. Horatio is not a prince, or even a Duke, and this is part of the reason that Lorenzo and Balthazar hate him, since, in loving Bel- Imperia, Horatio is usurping the position of the noble class. When Lorenzo hears that Bel-Imperia loves Horatio, he calls him "Don Horatio our Knight Marshal's son?" The Knight-Marshal could be considered something like the Attorney- General, or a Supreme Court Justice, the top lawyer and judge in the kingdom. But he is still merely a civil servant, far inferior in social rank to both Balthazar and Lorenzo, a prince and the son of a Duke. So Hieronimo's son is an upstart, who has humiliated them both on the battlefield, by capturing Balthazar and then gaining at least partial credit for it from Lorenzo. This partially explains their eagerness to avenge themselves for the perceived stain upon their honor.