The imagery she uses also reflects the pain that she experiences as she envisions the murder about to take place and the fact that she too will killed: she speaks of Clytemnestra as a lion: "Vengeance broodeth still, a lion's rage, which goes not forth to kill / But lurketh in his lair, watching the high hall…" Then she speaks of her as a wolf and as a serpent. The imagery is repeatedly of deadly animals, culminating in this terrible prophecy: "Some Skylla, deep / Housed in the rock, where sailors shriek and die, / Mother of Hell blood-raging, which doth cry / On her own flesh war, war without alloy…" Cassandra equates the revenge that Clytemnestra seeks with the revenge that the Greeks sought against Paris at Troy. War follows war -- even when peace is supposed and expected.

The narrative voice of Agamemnon is undisturbed by Cassandra's prophecy of the murder to come: on the contrary, it is heightened and made full. She intensifies the drama by...

Her voice, in fact, echoes the voice of the Chorus and brings to life the horror that lies at the heart of Agamemnon -- the fact that when one betrays the will of the gods (as Agamemnon did by his boast of being a better hunter than Artemis, or as Cassandra did when she rebuffed Apollo, or as Clytemnestra is about to do by murdering her husband), blood is sure to follow. One can literally hear the blood flowing in the words and lamentations of Cassandra as she predicts the events about to unfold.
In conclusion, Cassandra's speech prior to the murder of Agamemnon stands out because it draws the audience into the unique position of understanding the events taking place off-stage and gives an eloquent and horrific depiction in words of the violence that is not shown. Her speech reflects the overarching theme of the drama, which is that war follows war, and that the will of the gods is superior to that…