The assassins choose to attack under the cover of darkness to mask their identities. However, the very darkness they thought would assist them becomes the crutch in their plan. In Act II, Ross says something to the old man that makes sense in the context of the lamp’s destruction in Act III Scene III. Ross said, “By the clock 'tis day; / And yet night strangles the traveling lamp.” By including this comment, Shakespeare suggests a protracted battle between darkness and light, a conflict that extends throughout the play.
In direct contrast to the nature of their grisly actions, the hired killers’ language is both smooth and poetic. They note that “the west yet glimmers with some streaks of the day; / Now spurs the lated traveler apace / To gain the timely inn,” a clear demonstration of the gap between people’s words and actions (5-7). This does not seem the speech of murderers. Instead, the murderers demonstrate a sharp contrast between their words and actions.
Macbeth will not react well to news of Fleance’s escape. With Fleance still alive, the prophecy lives on. Banquo uses his last breath to reminds the audience of this fact before ordering Fleance to avenge his death. For Banquo, this will provide his ultimate victory over Macbeth.